Apparatus and process for forming a deposited film

ABSTRACT

A deposited film-forming apparatus comprising a reaction chamber capable of being vacuumed in which glow discharge is caused by means of a high frequency power supplied by a high frequency power introduction means to form a deposited film on a substrate positioned in said reaction chamber, wherein said high frequency power introduction means comprises an insulating material as a base constituent and has a region isolated from a glow discharge zone of said reaction chamber by means of said insulating material wherein an electrode comprising an electrically conductive metallic material having a thickness capable of sufficiently transmitting said high frequency power is disposed in said region such that it is contacted with said insulating material in a state with no clearance. A deposited film-forming process using said deposited film-forming apparatus.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an apparatus and process whichenables to efficiently form a deposited film including a functionaldeposited film such as an amorphous semiconductor film usable in variousdevices such as semiconductor device, electrophotographic lightreceiving member, image-input line sensor, image pickup device andphotovoltaic device, on a given substrate by way of plasma CVD process.

[0003] 2. Related Background Art

[0004] In recent years, there have been proposed a number of depositedfilms comprising amorphous materials such as amorphous silicons, e.g.,amorphous silicons in which dangling bonds are compensated by hydrogenatoms or/and halogen atoms, usable as semiconductors in semiconductordevices, electrophotographic light receiving members, image-input linesensors, image pickup devices, photovoltaic devices, or other electronicelements. Some of these deposited films have been practically using inthese devices, members or elements.

[0005] By the way, in the image-forming industrial field, for thephotoconductive material to constitute a light receiving layer in anelectrophotographic light receiving member, it is required to be highlysensitive, to have a high S/N ratio (photo-current (Ip)/dark current(Id)), to have absorption spectrum characteristics suited for anelectromagnetic wave to be irradiated, to be quickly responsive and tohave a desired dark resistance. It is also required to be not harmful toliving things, especially human body, upon use.

[0006] Particularly for electrophotographic light receiving members usedin an electropgotographic apparatus which is used as a business machineat the office, causing no pollution is highly important.

[0007] From these standpoints, public attention has been focused on a-Siseries light receiving members comprising amorphous silicon (a-Si)materials, for example, as disclosed in U.S. Pat. No. 4,265,991 whichdiscloses an electrophotographic light receiving having aphotoconductive layer constituted by an a-Si material and which excelsin moisture resistance, durability, and electric and photoconductivecharacteristics.

[0008] Besides, U.S. Pat. No. 4,788,120 discloses an electrophotographiclight receiving member having a surface protective layer constituted byan amorphous material containing silicon atoms, carbon atoms, andhydrogen atoms in an amount of 41 to 70 atomic %.

[0009] Based on these techniques, there has been realized a desirablea-Si series electrophotographic light receiving constituted by an a-Simaterial, which is satisfactory in electric, optical and photoconductivecharacteristics, use-environmental characteristics and durability, andenables to provide a high quality reproduced image.

[0010] In order to effectively produce such a desirable a-Si serieselectrophotographic light receiving member, an advanced technique isrequired. Particularly, for an a-Si series electrophotographic lightreceiving member, it is necessary to have a greater area and thicknessin comparison with other devices and because of this, not only to ensureuniformity but also to prevent abnormal film growth due to a nucleuscomprising a foreign matter during the deposition of an a-Si film areimportant factors.

[0011] In view of this, there are various proposals for stably andefficiently producing a high quality a-Si series electrophotographiclight receiving member on an industrial scale.

[0012] Incidentally, in the production of an a-Si serieselectrophotographic light receiving member, there has been pointed outthe occurrence of a spherical growth defect which becomes a cause ofentailing a defective image comprising a so-called “minute blank area”on an image reproduced. In most cases, such spherical growth defect isconsidered to occur due to abnormal film growth based on a particlegenerated when a film deposited on a inner face of a deposition chamberis removed.

[0013] Separately, for an electrophotographic light receiving memberproduced by a conventional manner, there has been pointed out a problemin that unevenness in density is sometimes occurred for an imagereproduced.

[0014] In order to solve these problems, there are also variousproposals.

[0015] Specifically, for example, Japanese Unexamined Patent PublicationNo. 4183871/1992 discloses a deposited film-forming process using amicrowave plasma CVD apparatus having a microwave introduction meanswith two different regions.

[0016] This document describes that by making the microwave introductionmeans to have a face, which is to be contacted with plasma generatedupon film formation, such that has a value of 2×10⁻² or less in terms ofa product of dielectric constant (∈) and dissipation factor (tan δ) withrespect to the frequency of a microwave used, stable discharge can becaused while preventing a film deposited on an inner face of adeposition chamber where a deposited film having an improved uniformityand which does not entail a defect for an image reproduced. And as anoptimal manner to do so, there is illustrate a technique of coating amicrowave introduction means with an alumina ceramic by way of a plasmaspraying process. According the technique described in the abovedocument, it is possible to form a high quality deposited film with afew of spherical growth defects.

[0017] Now, in recent years, there is an increased demand for anelectrophotographic apparatus to be improved in terms of its performanceso that it can provide a high quality reproduced image at a high speedand also in terms of its durability. In addition, there is an increaseddemand for the electrophotographic apparatus to be reduced the frequencyof maintenance works therefor by improving the reliability of itsconstituents.

[0018] Under this situation, for the electrophotographic light receivingmember used in the electrophotographic device, it has been improved sothat it can be continuously used under various environmental conditionsover a long period of time without conducting maintenance works.

[0019] However, for the electrophotographic light receiving member thusimproved, there are still some pints to be further improved.

[0020] Particularly, in the production of a light receiving memberproduced by the conventional deposited film-forming apparatus, there isan occasion in that there is afforded a light receiving member liable toentail a minute blanc area which is considered due to the foregoingspherical growth defect or a minute black area on an image reproduced,depending upon the film-forming conditions employed. Further, dependingupon the film-forming conditions employed, there is an occasion in thatthere is afforded a light receiving member which is liable to entail auneven density image on a reproduced image.

[0021] It becomes more important to eliminate these defects occurred onthe image reproduced as the image-forming speed and the sophysticationfor an image reproduced are progressed, because such defects due to atrifling defect or unevenness in characteristics occurred in thedeposited film which could be disregarded in ordinary cases, willapparently actualized in this case.

[0022] Herein, it should be noted to the fact that such defect orunevenness in characteristics occurred in the deposited film in theproduction of other semiconductor devices will entail a problem ofmaking the semiconductor devices such that are accompanied by a defector unevenness in characteristics.

SUMMARY OF THE INVENTION

[0023] An principal object of the present invention is to eliminate theforegoing problems in the prior art and to provide a plasma CVDapparatus and process which enable to efficiently form a high qualitydeposited film having an improved uniformity in characteristics bystably generating uniform plasma while uniformly supplying a highfrequency power without the high frequency power being localized andwithout the plasma being localized.

[0024] Another object of the present invention is to provide a plasmaCVD apparatus and process which enable to efficiently form a highquality deposited film by uniformly growing a film deposited whilepreventing the occurrence of abnormal film growth and while diminishingthe occurrence of the spherical growth defect (which results inentailing a defect such as minute blank area or black dot on areproduced image) found in the prior art.

[0025] A further object of the present invention is to provide a plasmaCVD apparatus and process which enable to efficiently form a highquality deposited film highly homogeneous over the entire of a surfaceof a substrate which is suitable particularly for use in anelectrophotographic light receiving member by stably generating uniformplasma without the plasma being localized.

[0026] A further object of the present invention is to provide adeposited film-forming apparatus comprising a reaction chamber capableof being vacuumed in which glow discharge is caused by means of a highfrequency power supplied by a high frequency power introduction means toform a deposited film on a substrate positioned in said reactionchamber, wherein said high frequency power introduction means comprisesan insulating material as a base constituent and has a region isolatedfrom a glow discharge zone of said reaction chamber by means of saidinsulating material wherein an electrode comprising an electricallyconductive metallic material having a thickness capable of sufficientlytransmitting said high frequency power is disposed in said region suchthat it is contacted with said insulating material in a state with noclearance.

[0027] A further object of the present invention is to provide adeposited film-forming process comprising introducing a raw material gasand a high frequency power into a reaction chamber capable of beingvacuumed and containing a substrate positioned therein to cause glowdischarge by means of said high frequency power whereby forming adeposited film on said substrate, wherein the introduction of said highfrequency power into said reaction chamber is conducted by a highfrequency power introduction means comprising an insulating material asa base constituent and having a region isolated from a glow dischargezone of said reaction chamber by means of said insulating material, andan electrode comprising an electrically conductive metallic materialhaving a thickness capable of sufficiently transmitting said highfrequency power being disposed in said region such that it is contactedwith said insulating material in a state with no clearance.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028]FIG. 1, FIG. 2, FIG. 3, FIG. 4 (FIGS. 4(a) and 4(b)), and FIG. 8are schematic cross-sectional views respectively illustrating apreferable example of a high frequency power introduction means in thepresent invention.

[0029]FIG. 5, FIG. 6 and FIG. 7 are schematic slant views respectivelyillustrating a preferable example of a high frequency power introductionmeans in the present invention.

[0030]FIG. 9 (FIGS. 9(a) and 9(b)) and FIG. 22 (FIGS. 22(a) and 22(b))are schematic diagrams respectively illustrating a depositedfilm-forming apparatus in which a high frequency power introductionmeans according to the present invention can be used.

[0031]FIG. 10, FIG. 11, FIG. 16, FIG. 17, FIG. 18 and FIG. 19 are graphsrespectively showing an example of a saturated electron currentdistribution.

[0032]FIG. 12 is a graph showing an example of unevenness in saturatedelectronic current.

[0033]FIG. 13 is a graph showing an example of deposition rate.

[0034]FIG. 14 and FIG. 20 are schematic cross-sectional viewsrespectively illustrating an example of a light receiving memberproduced according to the present invention.

[0035]FIG. 15 and FIG. 21 are graphs respectively showing the number ofspherical growth defects occurred in film formation.

DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS

[0036] An aspect of the present invention is directed to a depositedfilm-forming apparatus comprising a reaction chamber capable of beingvacuumed in which glow discharge is caused by means of a high frequencypower supplied by a high frequency power introduction means to form adeposited film on a substrate positioned in said reaction chamber,wherein said high frequency power introduction means comprises aninsulating material as a base constituent and has a region isolated froma glow discharge zone of said reaction chamber by means of saidinsulating material wherein an electrode comprising an electricallyconductive metallic material having a thickness capable of sufficientlytransmitting said high frequency power is disposed in said region suchthat it is contacted with said insulating material in a state with noclearance.

[0037] Another aspect of the present invention is directed to adeposited film-forming process comprising introducing a raw material gasand a high frequency power into a reaction chamber capable of beingvacuumed and containing a substrate positioned therein to cause glowdischarge by means of said high frequency power whereby forming adeposited film on said substrate, wherein the introduction of said highfrequency power into said reaction chamber is conducted by a highfrequency power introduction means comprising an insulating material asa base constituent and having a region isolated from a glow dischargezone of said reaction chamber by means of said insulating materialwherein an electrode comprising an electrically conductive metallicmaterial having a thickness capable of sufficiently transmitting saidhigh frequency power is disposed in said region such that it iscontacted with said insulating material in a state with no clearance.

[0038] For the metallic material (having the thickness capable ofsufficiently transmitting high frequency power) which is contacted withthe insulating material in the present invention, it is desired to beconfigured so that impedance is made to be discontinuous. Specifically,it may take a configuration in which the high frequency powerpropagation path is partly branched into plural portions, aconfiguration in which a part of the high frequency power propagationpath is turned up, or a coil-like configuration.

[0039] The insulating material as the base constituent of the highfrequency power introduction means (this will be hereinafter referred toas “insulating base material”) may be ceramics. The ceramics can includealumina ceramics.

[0040] In the present invention, it is possible to use a mechanism forcooling or heating the high frequency power introduction means.

[0041] The high frequency power introduction means in the presentinvention may be designed such that it serves also as a raw material gasintroduction means.

[0042] For the insulating base material constituting the high frequencypower introduction means, it has a portion to be exposed to glowdischarge and said portion is desired to have a surface roughness of 5μm to 200 μm in terms of JIS ten-point average roughness (RZ) under JISB0601.

[0043] In the present invention, as the high frequency power, it isdesired to use a high frequency power with an oscillation frequency of20 MHz to 450 MHz.

[0044] In the present invention, by forming an electrode in a regionisolated from the glow discharge zone in a contacted state by means ofthe insulating base material as above described, the occurrence of theforegoing spherical growth defect in a film deposited can be efficientlyprevented, whereby there can be attained the formation of a high qualitydeposited film which can be desirably used, for example, in anelectrophotographic light receiving member, wherein the light receivingmember is substantially free of a problem of entailing a uneven densityimage.

[0045] Particularly, according to the present invention, a desired highfrequency power can be uniformly supplied into a film-forming space(that is, a glow discharge space in other words) without being localizedto thereby stably generate uniform plasma in the film-forming space,where the growth of a film deposited uniformly progresses over theentire surface of a substrate. Because of this, there can be efficientlyformed a high quality deposited film substantially free of unevenness incharacteristics.

[0046] In addition, because of using the specific high frequency powerintroduction means according to the present invention, a film depositedon the surface thereof during film formation is difficult to be removedand because of this, the occurrence of the spherical growth defect inthe film deposited is effectively prevented.

[0047] Hence, the present invention enables to effectively eliminate theforegoing problems found in the prior art. Specifically, the presentinvention enables to concurrently attain a subject of preventing theresulting deposited film from being uneven in characteristics and asubject of preventing the resulting deposited film from having theproblem of entailing a minute blank area or black dot at a satisfactorylevel.

[0048] In the following, description will be made of anelectrophotographic light receiving member as an example.

[0049] As one of the factors to govern the yield of theelectrophotographic light receiving member, there can be mentioned theoccurrence of the foregoing spherical growth defect.

[0050] As a manner for preventing the occurrence of the spherical growthdefect, there can be mentioned the use of a high frequency powerintroduction means coated by an alumina ceramic or the like by means ofa plasma spraying process. The ceramic herein has a greater surfaceenergy in comparison with a metal and therefore, the surface of theceramic has a relatively strong adhesion with a film deposited thereon.To use this high frequency power introduction means is effective inpreventing layer peeling. However, this high frequency powerintroduction means is not sufficient enough for the following reasons.

[0051] That is, in general, on the surface of a conventional highfrequency power introduction means, film deposition is occurred at atemperature which is higher than that at which film deposition isoccurred on the surface of a substrate and the film deposited on thesurface of the high frequency power introduction means suffers fromexcessive ion bombardment due to a self-bias caused by a high frequencypower supplied, where a stress-strain diagram is accumulated in thedeposited film whereby the deposited film is removed from the highfrequency power introduction means. This layer peeling tends to becomesignificant when the high frequency power supplied is enlarged.

[0052] Under such condition as above described, even in the case ofusing the above-described high frequency power introduction means coatedby the alumina ceramic or the like by means of the plasma sprayingprocess, layer peeling of a film deposited thereon is sometimesoccurred.

[0053] In order to improve the adhesion of the deposited film with thesurface of the coat of the high frequency power introduction means, itis considered to make the surface of the coat have a increased surfaceroughness. However, in the case where the coat of the high frequencypower introduction means is formed by means of the plasma sprayingprocess, in order for the coat to have an increased surface roughness,it is necessary to use a spraying material having a large particle size,where the resulting coat layer becomes to have an undesirably largeporosity such that the coat layer is insufficient in adhesion with thesurface of the high frequency power introduction means and because ofthis, the coat layer itself is liable to peel from the high frequencypower introduction means.

[0054] In view of this, the present inventor made studies of a manner ofdisposing a cover made of a ceramic material on a surface of anelectrode as a high frequency power introduction means. As a result, itis found that this manner is liable to entail a problem in that adeposited film which is not homogenous in characteristics is sometimesafforded. The present inventor made studies of the reason for this. As aresult, it was found that the problem is principally due to a clearancecaused between the electrode and the ceramic cover.

[0055] For the interrelations among the occurrence of the problem (whichentails the formation of such non-homogenous deposited film), theelectrode and the ceramic cover, they are not clear enough for the timebeing. However, for the interrelations, it is considered as will bedescribed in the following.

[0056] In general, the propagation of a high frequency power isperformed in an dielectric portion between two electric conductors.

[0057] Herein, consideration is made of a deposited film-formingapparatus in which a plurality of cylindrical substrates as outerelectric conductors are concentrically arranged about an electrode as ahigh frequency power introduction means (this electrode will behereinafter referred to as center electric conductor). In this case, incomparison with the space between the center electric conductor and eachcylindrical substrate (the outer electric conductor), the space of theclearance between the electrode and the ceramic cover is negligiblysmall.

[0058] On the other hand, when glow discharge is occurred, plasmagenerated is considered to behave as a kind of electric conductor andtherefore, a load impedance is greatly governed by the situation of asheath region formed in the vicinity of the electrode. In this case, theinfluence of the clearance between the electrode and the ceramic coveris not disregarded. Particularly, the glow discharge is greatlyinfluenced by a variation in the clearance between the electrode and theceramic cover.

[0059] For instance, in the case where the clearance between theelectrode and ceramic cover is not uniform due to a certain trouble inthe mechanical processing, there is an occasion in that glow dischargeis markedly localized.

[0060] In addition, when the temperature of the electrode is raisedduring the glow discharge, the electrode is expanded to greatly changethe size of the clearance present between the electrode and the ceramiccover, where the matching conditions for the glow discharge aresometimes markedly varied.

[0061] Such localization and variation of the glow discharge not onlyresult in making the resulting light receiving member have an unevennessin characteristics but also result in depositing a readily peelable filmon the surface of the ceramic cover, where the film deposited on thesurface of the ceramic cover is sometimes peeled during the filmformation to cause the occurrence of a spherical growth defect in a filmdeposited on the substrate. This situation tends to become apparent asthe wattage of the high frequency power or the oscillation frequencythereof is increased.

[0062] To completely eliminate the clearance between the electrode andthe ceramic cover is extremely difficult in practice. For instance, inthe case where thermal expansion is occurred in the electrode, it isnecessary to intentionally provide a certain clearance between theelectrode and the ceramic cover because of a difference between theircoefficients of thermal expansion. Further, in the case where theelectrode and the ceramic cover are mechanically caulked, the toughnessof the ceramic material constituting the ceramic cover is inferior tothat of the metallic material constituting the electrode and because ofthis, it is necessary to intentionally provide a certain clearancebetween the two in order to prevent the occurrence of a damage.

[0063] Therefore, in any case, it is required to intentionally provide acertain clearance between the electrode and the ceramic cover.

[0064] Now, the results obtained as a result of experimental studies bythe present inventor revealed that there is a tendency in that as theclearance between the electrode and ceramic cover is diminished, thestate for glow discharge generated becomes uneven accordingly and thatthere is a tendency in that as the clearance is enlarged, the loss inthe high frequency power is increased accordingly.

[0065] For the reason why the resulting deposited film is nothomogeneous in characteristics, it is considered principally due tounevenness in a high frequency power supplied into the plasma from ahigh frequency power introduction means.

[0066] In the case of a conventional high frequency power introductionmeans, there is a tendency in that the high frequency power irradiatedbecomes relatively intense at opposite end portions of the highfrequency power introduction means (substantially, opposite end portionsof a portion thereof to radiate a high frequency power into the plasma)and it becomes relatively weak about the central portion thereof. Thereason for this is considered such that high frequency powers generatedon the surface of the high frequency power introduction means aremultiple-reflected to influence (or interfere) with each other so as toweaken.

[0067] This tendency becomes significant as the frequency (theoscillation frequency) of the high frequency power is increased, forinstance, in order to increase the deposition rate for a film deposited.For the reason for this, it is considered such that when the frequencyof the high frequency power approximates to the effective length of thehigh frequency power introduction means, the above described highfrequency power-interfering phenomenon becomes apparent.

[0068] Separately, there is a tendency in that when the wattage of thehigh frequency power is increased, the high frequency power irradiatedat opposite end portions of the high frequency power introduction meansbecomes to be in a saturated state for a raw material gas, and the highfrequency power irradiated at the central portion thereof is relativelyincreased in terms of intensity. In this case, the resulting depositedfilm becomes such that is small in terms of unevenness incharacteristics.

[0069] The difference between the high frequency power at the centralportion and that at the opposite end portions is not so large that thedeposition rate for a film deposited on a substrate is influenced. Butthe difference is appeared as a difference in the saturated electroncurrent and this results in imparting a negative influence to theproperty of the film deposited. Particularly, there is caused a subtledifference the photosensitivity. For instance, in the case of anelectrophotographic light receiving member comprising such depositedfilm, when a halftone original is reproduced, there is sometimesreproduced an uneven halftone image.

[0070] As previously described, the minute blanc area is occurred due tothe abnormal film growth based on the spherical growth defect caused bya particle released from the deposited film peeled during the filmformation. For a deposited film having such spherical growth defect,there is often present a gap at the boundary between the sphericalgrowth defect and the deposited film. In this case, a charge escapesthrough the gap, where charging cannot be sufficiently carried out asdesired and because of this, there entails a minute blank area on animage reproduced.

[0071] In order to prevent the occurrence of the spherical growthdefect, it is considered to use the foregoing high frequency powerintroduction means coated by an alumina ceramic or the like by means ofthe plasma spraying process. However, the use of this high frequencypower introduction means is still problematic as previously described.Particularly in this respect, as previously described, on the surface ofthe conventional high frequency introduction means, film deposition isoccurred at a temperature which is higher than that at which filmdeposition is occurred on the surface of the substrate and the filmdeposited on the surface of the high frequency power introduction meanssuffers from excessive ion bombardment due to the self-bias caused bythe high frequency power supplied, where the stress-strain diagram isaccumulated in the deposited film on the high frequency powerintroduction means whereby the deposited film is peeled. Under thiscondition, even when the high frequency power introduction means coatedby the alumina ceramic or the like by means of the plasma sprayingprocess is used, the film deposited on the surface of this highfrequency power introduction means is liable to peel. In order toimprove the adhesion of the deposited film with the surface of the coatof the high frequency power introduction means, it is considered to makethe surface of the coat have a increased surface roughness. However, inthe case where the coat of the high frequency power introduction meansis formed by means of the plasma spraying process, in order for the coatto have an increased surface roughness, it is necessary to use aspraying material having a large particle size, where the resulting coatlayer becomes to have an undesirably large porosity such that the coatlayer is insufficient in adhesion with the surface of the high frequencypower introduction means and because of this, the coat layer itself isliable to remove from the high frequency power introduction means. Thissometimes results in increasing the possibility of entailing theoccurrence of a minute blank area on an image reproduced.

[0072] Now, for a deposited film formed on the substrate, the occurrenceof an unevenness in characteristics based on the unevenness in the highfrequency power supplied may be prevented at a certain extent by raisingthe wattage of the high frequency power. However, for anelectrophotographic light receiving member comprising a deposited filmformed with the use of a high frequency power of an increased wattage,the present inventor found that it is liable to provide a reproducedimage accompanied by an undesirable black dot. The present inventor madeexamination of this electrophotographic light receiving member. As aresult, the deposited film of the electrophotographic light receivingmember was found to have minute upheavals at the surface thereof. Suchupheaval was found to be of less than 10 um in diameter and to have nodistinct boundary thereabout as in the case of the spherical growthdefect. Herein, the spherical growth defect (which entails a cause ofproviding a minute blank area on an image-reproduced) is usually morethan 10 um in diameter.

[0073] In the case of the above-described electrophotographic lightreceiving member with minute upheavals, charging and charge-eliminationat the portion with the minute upheavals can be normally performed aswell as at the remaining portion with no such upheaval at the beginningstage, where a defect due to the minute upheavals is not entailed on animage reproduced. However, when the electrophotographic image-formingprocess is continuously repeated over a long period of time, toner isfuse-welded due to the upheavals to result in entailing a black dot onan image reproduced.

[0074] Such upheaval is liable to occur when the high frequency power isexcessively supplied during the film formation. In fact, the presentinventor obtained a finding that when an electrophotographic lightreceiving member is produced using a high frequency power of anexcessive wattage, such upheaval is liable to occur at its upper andlower portions. This fact indicates that the occurrence of such upheavalis caused when a high frequency power is excessively supplied during thefilm formation.

[0075] As apparent from the above description, it is understood thataccording to the conventional high frequency power introduction means,it is difficult to concurrently attain the prevention of the occurrenceof unevenness in characteristics for a deposited film formed and theprevention of the occurrence of a minute blank area on an imagereproduced at an improved level.

[0076] The present invention is based on the above analysis of the priorart.

[0077] The present invention is featured in using a specific highfrequency power introduction means configured as above described and itenables to efficiently produce a desirable electrophotographic lightreceiving member while effectively preventing the occurrence ofunevenness in characteristics for a deposited film formed so that theoccurrence of a minute blank area on an image reproduced is desirablyprevented.

[0078] As previously described, the high frequency power introductionmeans used in the present invention comprises an insulating material asthe base constituent and a region isolated from a glow discharge zone ofa film-forming space (or a reaction chamber) by means of said insulatingmaterial and a metallic material (serving as an electrode) having athickness capable of sufficiently transmitting a high frequency powerwhich is disposed in said region such that said metallic material iscontacted with said insulating material. This high frequency powerintroduction means is free of such clearance as found in theconventional high frequency power introduction means. And in comparisonwith the conventional high frequency power introduction means comprisingan electrode coated by an insulating material, the physical strength ofthe insulating in the high frequency power introduction means in thepresent invention is markedly greater than that of the insulatingmaterial as the coat of the conventional high frequency powerintroduction means. In the present invention, such problem that the coatof the high frequency power generation means is peeled to release aforeign matter in a particle form which results in forming a sphericalgrowth defect in a film deposited is not entailed. Particularly, the useof the high frequency power introduction means according to the presentinvention enables to generate stable discharge in a uniform statewithout being localized and without causing such spherical growth defectbased on the foreign matter in a film deposited.

[0079] Further, the present invention is based on those findingsobtained by the present inventor which will be described below.

[0080] The present inventor made experimental studies in order toestablish a reliable high frequency power introduction means which canattain improved uniformalization for a high frequency power supplied. Asa result, there was obtained a finding that in order to effectivelyprevent a high frequency power supplied from being localized, toconfigure the high frequency power introduction means to have an areacapable of making impedance to be discontinuous (this area will behereinafter referred to as impedance discontinuous area) is effective.

[0081] Particularly, when the high frequency power introduction means isthus configured, a high frequency power irradiated from the highfrequency power introduction means is reflected not only at opposite endportions of the high frequency power introduction means but also at theimpedance discontinuous area, where the high frequency powers irradiatedare prevented from influencing (or interfering) with each other touniformalize. In addition, since the electrode (comprising anelectrically conductive metallic material) is covered by the insulatingmaterial, the impedance discontinuous area effectively functions as areflecting surface for a high frequency power and because of this, thereis provided a pronounced advantage in that a high frequency power isuniformly irradiated in the film-forming space. Further, even in thecase where the electrode in the high frequency power introduction meansis made to have a complicated structure, the occurrence of sparking iseffectively prevented because of the presence of the impedancediscontinuous area.

[0082] Further in addition, in the high frequency power introductionmeans according to the present invention, the electrode is tightlyjoined to the inside of the insulating material (on the side of thespace isolated from the discharge space of the film-forming space by theinsulating material) in a state with no clearance between the twomembers, where the foregoing problem occurred in the case of using theconventional high frequency power introduction means in that the highfrequency power is unevenly irradiated due to the clearance presentbetween the insulating coat and the electrode is not occurred.

[0083] Hence, the present invention enables to effectively eliminate theforegoing problems for devices having a thin deposited film such asamorphous silicon devices which are found in the prior art.

[0084] In the following, the present invention will be described in moredetail.

[0085] As previously described, the high frequency power introductionmeans used in the present invention comprises an insulating material asa base constituent and has a region isolated from a glow discharge zoneof a film-forming space (or a reaction chamber) by means of saidinsulating material wherein an electrode comprising an electricallyconductive metallic material capable of transmitting a high frequencypower is disposed in said region such that it is contacted with saidinsulating material in a state with no clearance.

[0086] Herein, if necessary, the high frequency power introduction meansaccording to the present invention may be designed so as to serve alsoas a raw material gas supply means.

[0087] As the insulating material constituting the high frequency powerintroduction means, it is desired to use an insulating material having agood adhesion with a film deposited on the surface of the high frequencypower introduction means. Specific examples of such insulating materialare glasses such as quartz glass, pyrex glass and the like; and ceramicssuch as alumina ceramics, titanium dioxide, boron nitride, zircon,cordierite, zircon-cordierite, silicon oxide, beryllium oxide, micaceramics, and the like. Of these, in view of durability and adhesionwith a film deposited, ceramics are preferable. Partcularly, aluminaceramics are the most preferable because they excel in durability andadhesion with a film deposited and are slight in absorption of a highfrequency power.

[0088] For the insulating material as the base constituent of the highfrequency power introduction means and the electrode, each of them isdesired to be configured in a cylindrical form (or a circular cylinderform) in view of workability and formation easiness. And it is desiredfor the insulating material and the electrode to be concentricallyarranged for the same reasons.

[0089] As previously described, the insulating material of the highfrequency power introduction means has a surface to be exposed to thedischarge zone (or the discharge space) of the film-forming space (orthe reaction chamber). This surface of the insulating material may be aroughened surface provided with irregularities mainly for the purpose ofpreventing a film deposited thereon from being peeled.

[0090] For the roughened surface of the insulating material in thiscase, it is desired to be of a surface roughness of 5 μm to 200 μm interms of JIS ten-point average roughness (RZ) under JIS B0601.

[0091] Such roughened surface may formed, for instance, by aconventional blasting process using an abrasive.

[0092] For the size of the insulating material as the base constituentof the high frequency power introduction means, there is no particularlimitation.

[0093] However, in the case where the high frequency power introductionmeans shaped in a cylindrical form (designed so as to serve also as araw material gas supply means) is arranged in the discharge spacecircumscribed by a plurality of electrically conductive cylindricalsubstrates spacedly arranged on a concentric circle, the size of thecylindrical insulating material (that is, the outer diameter of thecylindrical high frequency power introduction means) is desired to be ofa magnitude of 4% to 25% of the diameter of the circumference where thecylindrical substrates are specedly arranged.

[0094] For the thickness of the cylindrical insulating material, thereis no particular limitation. However, in general, it is desired to be inthe range of 0.5 to 20 mm in view of workability and physical strength.

[0095] For the diameter of the cylindrical electrode, there is noparticular limitation as long as it matches with the diameter andthickness of the cylindrical insulating material. However, in general,it is desired to be 2 mm or more in view of practicability.

[0096] For the length of the high frequency power introduction means, ingeneral, it is desired to be of a magnitude of 100% to 150% of thelength of a substrate on which a film is to be deposited. However, evenin the case where the length of the high frequency power introductionmeans is of a magnitude of less than 100% of the length of thesubstrate, the advantages of the present invention are provided. Thelength of the high frequency power introduction means herein indicatesan effective portion of the high frequency power introduction meanswhich serves to substantially radiate a high frequency power into thedischarge space of the film-forming space.

[0097] As previously described, the electrode of the high frequencypower introduction means is constituted by an appropriate electricallyconductive metallic material. The electrically conductive metallicmaterial can include metals such as Al, Cr, Cu, Mo, Au, Ag, In, Nb, Ni,Te, V, Ti, Pt, Pb and Fe; and alloys of these metals such as stainlesssteel, inconel, hastelloy, and the like.

[0098] For the thickness of the electrode, it should be determined in arange capable of sufficiently transmitting a high frequency power.Specifically, the thickness should be determined so that it is greaterthan a skin effect decided depending upon the oscillation frequency of ahigh frequency power used and the kind of an electrically conductivemetallic material by which the electrode is constituted.

[0099] For instance, in the case where the oscillation frequency of thehigh frequency power is 105 MHz and the electrode is constituted bycopper (Cu), the skin effect is about 7 μm. In this case, the thicknessof the electrode is made to be 7 μm or more.

[0100] In the case where the thickness of the electrode is excessivelylarge, when the temperature of the electrode is greatly raised, aremoval is liable to occur at the interface between the electrode andthe insulating material due to a difference between their coefficientsof expansion. Therefore, the upper limit for the thickness of theelectrode is desired to properly determined having a due care aboutconditions employed for film formation.

[0101] To contact the electrode with the insulating material in a statewith no clearance may be conducted by an appropriate manner such aschemical plating, thermal spraying, sputtering, brazing, solid diffusionwelding, plasma spraying, plasma CVD or vacuum evaporation.

[0102] In the present invention, the electrode is desired to beconfigured to have an impedance-discontinuing area in which theimpedance is made to be discontinuous. For this purpose, an appropriateconfiguration may be employed as long as a desirable impedancediscontinuous area is provided. Specific examples of such configurationare a configuration in which the high frequency power propagation pathis partly branched into plural portions, a configuration in which a partof the high frequency power propagation path is turned up, and acoil-like configuration.

[0103] For the position for the impedance-discontinuing area to beprovided, it should be determined depending upon conditions employed forfilm formation, so that the high frequency power introduction meansirradiates a high frequency power into the discharge space in anoptimally uniform state.

[0104] In the inside of the high frequency power introduction means(that is, on the side isolated from the glow discharge zone), there isoccurred a cavity depending upon a combination of the size (thediameter) and thickness of the insulating material and the thickness ofthe electrode. This cavity may be maintained in a vacuumed state or itmay be isolated from the vacuum system of the film-forming space (or thereaction chamber) by way of vacuum sealing.

[0105] In any case, it is desired to prevent a raw material gas fromflowing into the inside of the high frequency power introduction meansin order to prevent the raw material gas from staying therein.

[0106] It is possible for the cavity to be filled by an appropriatefilling material. The filling material used in this case can includeinsulating materials capable of using as the constituent of theinsulating material of the high frequency power introduction means,electrically conductive metallic materials capable of using as theconstituent of the electrode, and synthetic resins such aspolycarbonate, Teflon (trademark name), polyamide, and polyimide. Thefilling materials may be filled in the cavity in a state in that itcontacts with the face of the electrode on the cavity side or in a statein that it has a clearance to said face. Particularly, when a problemrelating to thermal expansion would occur, it is possible to providesaid clearance at an appropriate magnitude of 0.1 to 5 mm. For the casewhere this clearance was provided, the present inventor madeexperimental studies. As a result, there was not observed asubstantially negative influence due to the clearance, where a highfrequency power was irradiated principally from a portion of the highfrequency power introduction means faced to the glow discharge zone (orthe discharge space) of the film-forming space.

[0107] For the number of the high frequency power introduction meansused in the film-forming space, it may be one or more. In the case ofconducting film formation in a system in that a plurality ofelectrically conductive cylindrical substrate are spacedly arranged tocircumscribe a discharge space (or a glow discharge zone) by using asingle high frequency power introduction means, it is desired for thehigh frequency power introduction means to be positioned on a coaxialline at the center of the arrangement circle of the cylindricalsubstrates (inside the arrangement circle of the cylindrical substrates)in order for a high frequency power to be uniformly irradiated towardevery cylindrical substrate.

[0108] In the case of using a plurality of high frequency powergeneration means in the above system, they are desired to be spacedlyarranged on a circumference concentric to the arrangement circle of thecylindrical substrates. The arrangement circle of these high frequencypower introduction means in this case may be smaller or larger than thearrangement circle of the cylindrical substrates. Particularly in thisrespect, these high frequency power introduction means may be arrangedon a circumference concentric to the arrangement circle of thecylindrical substrates at a position outside or inside the arrangementcircle of the cylindrical substrates. When these high frequency powerintroduction means are arranged on a circumference concentric to thearrangement circle of the cylindrical substrates at a position outsidethe arrangement circle of the cylindrical substrates, at least one ofthese high frequency power introduction means is desired to be arrangedat a position inside the arrangement circle of the cylindricalsubstrates.

[0109] Further, in the case of using two high frequency powerintroduction means, they may be arranged in such a state in that theyare divided in a generatrix direction. The two high frequency powerintroduction means are desired to be positioned on a coaxial line at thecenter of the arrangement circle of the cylindrical substrates (insidethe arrangement circle of the cylindrical substrates).

[0110] In the present invention, it is possible to use a means forheating or cooling the high frequency power introduction means. In thiscase, for example, by controlling the temperature of the high frequencypower introduction means to a desired temperature by the heating meansduring film formation, the adhesion of the surface of the insulatingmaterial of the high frequency power introduction means with a filmdeposited thereon is improved to prevent the deposited film from peelingtherefrom.

[0111] To heat or cool the high frequency power introduction meansshould be decided depending upon related conditions such as acombination of the kind of a film to be formed and the kind of theconstituent of the insulating material of the high frequency powerintroduction means, the wattage of a high frequency power used, theinner pressure in the film-forming space upon film formation, the flowrate of a raw material gas introduced into the film-forming space, andthe like.

[0112] As previously described, the high frequency power introductionmeans according to the present invention may be designed so that it canserve also as a raw material gas supply means. In this case, theinsulating material of the high frequency power introduction means maybe configured to have a gas flow pathway and one or more gas releaseholes communicated with the gas flow pathway wherein the gas flow pathway is connected to a raw material gas supply system containing gasreservoirs. In this case, a raw material gas from the raw material gassupply system passes through the gas glow pathway of the insulatingmaterial and flows into the discharge space from the gas releasehole(s).

[0113] In the film formation in the present invention, a high frequencypower of a given wattage is supplied by the high frequency powerintroduction means into the discharge space containing a raw materialgas to generate glow discharge thereby causing plasma, where the rawmaterial gas is decomposed to cause the formation of a deposited film ona substrate.

[0114] For the oscillation frequency of a high frequency power used inthe present invention, there is no particular limitation. However, theresults obtained as a result of experimental studies by the presentinventor provided the following findings. That is, when a high frequencypower with an oscillation frequency of less than 20 MHz is used, thereis occasionally caused unstable glow discharge under certainfilm-forming conditions and therefore, there is a limitation for thefilm-forming conditions to be employed. And when a high frequency powerwith an oscillation frequency of beyond 450 MHz is used, there is atendency for the transmission characteristic-of the high frequency powerto be deteriorated so that glow discharge is difficult to be generated.

[0115] In this respect, to use a high frequency power with anoscillation frequency in the range of from 20 MHz to 450 MHz is the mostdesirable.

[0116] For the wattage of a high frequency power used in the presentinvention, it should be determined depending upon the characteristics orthe like desired for a deposited film to be formed. However, in general,it is desired to be preferably in the range of from 10 W to 5000 W, morepreferably in the range of from 20 W to 2000 W per one substrate.

[0117] In the following, description will be made of a depositedfilm-forming apparatus according to the present invention with referenceto the drawings.

[0118]FIG. 1 is a schematic cross-sectional view in a generatrixdirection of a preferable example of a high frequency power introductionmeans according to the present invention.

[0119] In FIG. 1, reference numeral 102 indicates a high frequency powerintroduction means shaped in a cylindrical form which comprises acylindrical insulating material 111 and an electrode 112.

[0120] A space (with no reference numeral) outside the insulatingmaterial 111 is a glow discharge zone (or a discharge space) of afilm-forming space (or a reaction chamber).

[0121] As apparent from FIG. 1, the electrode 112 is formed on an insideface of the insulating material 111 (that is, on a surface of theinsulating material on the side of a region 113 isolated from the glowdischarge zone) such that the electrode 112 is joined with the insideface of the insulating material 111 in a state with no clearance.

[0122] The region 113 (comprising a cavity) is formed inside theelectrode 112 and is isolated from the glow discharge zone (the regionwill be hereinafter referred to as isolated region). The region 113 (thecavity) is isolated from the vacuum system of the film-forming space bya vacuum sealing means (not shown) so that no raw material gas is flowntherein.

[0123] The upper tip of the electrode 112 is electrically connectedthrough a high frequency power input terminal (not shown) to a highfrequency power source provided with a high frequency power transmissioncircuit (not shown).

[0124] In the embodiment shown in FIG. 1, the lower tip of theinsulating material 111 (that is, the tip of the insulating material 111on the side where no high frequency power input terminal is present) hasa closed structure as shown in FIG. 1. However, this is not restrictive.It is possible to take a configuration with open opposite ends, forinstance, a cylindrical configuration.

[0125]FIG. 2 is a schematic cross-sectional view in a generatrixdirection of another preferable example of a high frequency powerintroduction means according to the present invention.

[0126] A cylindrical high frequency power introduction means 102 shapedin a cylindrical form shown in FIG. 2 is a modification of the highfrequency power introduction means shown in FIG. 1 such that a metal baris embedded in the cavity as the isolated region of the high frequencypower introduction means shown in FIG. 1. Particularly, the constitutionof the high frequency power introduction means shown in FIG. 2 is thesame as that of the high frequency power introduction means shown inFIG. 1, except that a metal bar 115 is disposed in the cavity as theisolated region.

[0127] In the high frequency power introduction means 102 shown in FIG.2, an electrode 112 is formed on an inside face of a cylindricalinsulating material ill such that the electrode 112 is joined with theinside face of the insulating material 111 in a state with no clearanceand an isolated region 113 (a cavity) formed inside the electrode 112,wherein the metal bar 115 is arranged in the cavity 113 in a state witha clearance 114 between the electrode 112 and the metal bar 115 as shownin FIG. 2.

[0128]FIG. 3 is a schematic cross-sectional view in a generatrixdirection of a further preferable example of a high frequency powerintroduction means according to the present invention.

[0129] A high frequency power introduction means 102 shaped in acylindrical form shown in FIG. 3 is a modification of the high frequencypower introduction means shown in FIG. 1 such that a cooling mechanismis provided in the configuration of the high frequency powerintroduction means shown in FIG. 1.

[0130] In the high frequency power introduction means 102 shown FIG. 3,an electrode 112 is formed on an inside face of a cylindrical insulatingmaterial 111 such that the electrode 112 is joined with the inside faceof the insulating material 111 in a state with no clearance, and acavity 113 as an isolated region is formed inside the electrode 112. Thecavity 113 is vacuum-sealed by a vacuum-sealing means 130 so as toisolate from the vacuum system of the film-forming space in order toprevent a raw material gas from flowing into the cavity 113.

[0131] And the high frequency power introduction means shown in FIG. 3is provided with a cooling mechanism comprising a cooling mediumintroduction pipe 120 having a cooling medium inlet port 119 and whichis extended through the vacuum-sealing means 130 into the cavity 113while being open into the cavity 113 and an cooling medium exhaustmechanism with a cooling medium outlet port 121 and which is providedthrough the vacuum-sealing means 130.

[0132] In the high frequency power introduction means shown in FIG. 3, acooling medium from a cooling medium supply device (not shown) isintroduced into the cavity 113 through the inlet port 119 and theintroduction pipe 120 to cool the electrode 112 and thereafter, thecooling medium is exhausted to the outside through the outlet port 121of the exhaust mechanism.

[0133] This embodiment is of the case of cooling the high frequencypower introduction means by means of the cooling medium. But this is notrestrictive. It is possible to heat the high frequency powerintroduction means by replacing the cooling medium by a heating medium.Besides this, to heat the high frequency power introduction means may beconducted by using a heater disposed in the cavity 113.

[0134] FIGS. 4(a) and 4(b) are schematic cross-sectional viewsillustrating a preferable of a high frequency power introduction meanscapable of serving also as a raw material gas introduction meansaccording to the present invention.

[0135]FIG. 4(b) is a schematic cross-sectional view in a generatrixdirection. FIG. 4(a) is a schematic cross-sectional view, takenalong-the line A-A′ in FIG. 4(b).

[0136] A high frequency power introduction means 102 shaped in acylindrical form shown in FIGS. 4(a) and 4(b) is a modification of thehigh frequency power introduction means shown in FIG. 1 such that a rawmaterial gas introduction mechanism is provided in the configuration ofthe high frequency power introduction means shown in FIG. 1.

[0137] In the high frequency power introduction means shown in FIGS.4(a) and 4(b), an electrode 112 is formed on an inside face of acylindrical insulating material 111 such that the electrode 112 isjoined with the inside face of the insulating material 111 in a statewith no clearance, and a cavity 113 as an isolated region is formedinside the electrode 112. The cavity 113 is vacuum-sealed by avacuum-sealing means (not shown) so as to isolate from the vacuum systemof the film-forming space in order to prevent a raw material gas fromflowing into the cavity 113.

[0138] As well as in the case of the high frequency power introductionmeans shown in FIG. 1, the upper tip of the electrode 112 iselectrically connected through a high frequency power input terminal(not shown) to a high frequency power source provided with a highfrequency power transmission circuit (not shown).

[0139] The insulating material 111 is provided with a plurality of gasflow pathways 118 formed in the inside thereof. Each of the gas flowpathways 118 has a raw material gas inlet port 117 which is connected toa raw material gas supply system (not shown) containing gas reservoirs(not shown). The insulating material 111 is provided with a plurality ofgas release holes 116 at its outer surface on the glow discharge zoneside. Each of the gas release holes 116 is formed so as to communicatewith one of the gas flow pathways 118.

[0140] In the high frequency power introduction means shown in FIGS.4(a) and 4(b), a raw material gas from the raw material gas supplysystem is introduced into the gas flow pathways 118 through the rawmaterial gas inlet ports 117 and the raw material gas thus introducedinto the gas flow pathways 118 is successively released into the glowdischarge zone through the gas release holes 116.

[0141]FIG. 5 is a schematic slant view illustrating an example of a highfrequency power introduction means according to the present invention inwhich the electrode (the high frequency power propagation path) ispartly branched into plural portions so that the impedance is made to bediscontinuous.

[0142] In FIG. 5, reference numeral 102 indicates a high frequency powerintroduction means shaped in a cylindrical form which comprises acylindrical insulating material 111 and an electrode 112 (which ispartly branched into plural portions so that the impedance is made to bediscontinuous).

[0143] A space (with no reference numeral) outside the insulatingmaterial 111 is a glow discharge zone (or a discharge space) of afilm-forming space (or a reaction chamber).

[0144] As apparent from FIG. 5, the electrode 112 is formed on an insideface of the insulating material 111 (that is, on a surface of theinsulating material on the side of a region 113 isolated from the glowdischarge zone) such that the electrode 112 is joined with the insideface of the insulating material 111 in a state with no clearance.

[0145] The region 113 (comprising a cavity) is formed inside theelectrode 112 and is isolated from the glow discharge zone. The cavity113 is vacuum-sealed by a vacuum-sealing means (not shown) so as toisolate from the vacuum system of the film-forming space in order toprevent a raw material gas from flowing into the cavity 113.

[0146] The upper tip of the electrode 112 is electrically connectedthrough a high frequency power input terminal (not shown) to a highfrequency power source provided with a high frequency power transmissioncircuit (not shown).

[0147] In the high frequency power introduction means shown in FIG. 5,the electrode 112 is configured to have two branched paths inside theinsulating material 111 (this corresponds a pattern in which a part ofthe electrode 112 in FIG. 1 is omitted). The electrode 112 thusconfigured comprises three regions A, B and C which make the impedanceto be discontinuous.

[0148]FIG. 6 is a schematic slant view illustrating an example of a highfrequency power introduction means according to the present invention inwhich a part of the electrode 112 (the high frequency power propagationpath) is turned up so that the impedance is made to be discontinuous(this corresponds a pattern in which a part of the electrode 112 in FIG.1 is omitted). The electrode 112 thus configured comprises three regionsA, B and C which make the impedance to be discontinuous.

[0149]FIG. 7 is a schematic slant view illustrating an example of a highfrequency power introduction means according to the present invention inwhich a part of the electrode 112 (the high frequency power propagationpath) is coil-like shaped (or spiraled) so that the impedance is made tobe discontinuous. The electrode 112 thus configured comprises threeregions A, B and C which make the impedance to be discontinuous.

[0150]FIG. 8 is a schematic cross-sectional view in a generatrixdirection of an example of a high frequency power introduction meansprovided with a cooling mechanism according to the present invention.

[0151] In the high frequency power introduction means 102 shown FIG. 8,an electrode 112 is formed on an inside face of a cylindrical insulatingmaterial 111 such that the electrode 112 is joined with the inside faceof the insulating material 111 in a state with no clearance, and acavity 113 as an isolated region is formed inside the electrode 112. Theelectrode 112 situated inside the insulating material 111 is configuredto have two branched paths so that the impedance is made to bediscontinuous.

[0152] The cavity 113 is vacuum-sealed by a vacuum-sealing means 130 soas to isolate from the vacuum system of the film-forming space in orderto prevent a raw material gas from flowing into the cavity 113.

[0153] And the high frequency power introduction means shown in FIG. 8is provided with a cooling mechanism comprising a cooling mediumintroduction pipe 120 having a cooling medium inlet port 119 and whichis extended through the vacuum-sealing means 130 into the cavity 113while being open into the cavity 113 and an cooling medium exhaustmechanism with a cooling medium outlet port 121 and which is providedthrough the vacuum-sealing means 130.

[0154] In the high frequency power introduction means shown in FIG. 8, acooling medium from a cooling medium supply device (not shown) isintroduced into the cavity 113 through the inlet port 119 and theintroduction pipe 120 to cool the electrode 112 and thereafter, thecooling medium is exhausted to the outside through the outlet port 121of the exhaust mechanism.

[0155] This embodiment is of the case of cooling the high frequencypower introduction means by means of the cooling medium. But this is notrestrictive. It is possible to heat the high frequency powerintroduction means by replacing the cooling medium by a heating medium.Besides this, to heat the high frequency power introduction means may beconducted by using a heater disposed in the cavity 113.

[0156] FIGS. 9(a) and 9(b) are schematic diagrams illustrating anexample of a plasma CVD apparatus capable of forming a deposited film ona plurality of substrates at the same time in which a high frequencypower introduction means according to the present invention can be used.

[0157] The apparatus shown in FIGS. 9(a) and 9(b) comprises a reactionchamber 100, a raw material gas supply system (not shown) containing gasreservoirs (not shown), an exhaust system (not shown) containing avacuuming device (not shown), and a high frequency power source 107 forsupplying a high frequency power to a high frequency power introductionmeans 102.

[0158] The reaction chamber 100 has a structure capable of beingvacuumed, and it is provided with an exhaust system containing anexhaust pipe which is open into the reaction chamber and which isconnected through a main valve (not shown) to a vacuuming device (notshown).

[0159] In the reaction chamber 100, a plurality of rotatable cylindricalsubstrate holders are spacedly and concentrically arranged so as tocircumscribe a glow discharge space 103. Each cylindrical substrateholder is supported by a rotary shaft 108 connected to a drivingmechanism including a gear 110 and a driving motor 109. Each cylindricalsubstrate holder has an electrically conductive substrate 101 in acylindrical form (on which a deposited film is to be formed) positionedthereon. Each cylindrical substrate holder has a heater 104 installedtherein for heating the substrate 101 positioned thereon.

[0160] In FIGS. 9(a) and 9(b), there are shown eight cylindricalsubstrate holders. This is not restrictive. The number of thecylindrical substrate holder to be arranged in the reaction chamber 100may be optionally changed depending upon the situation, provided that anappropriate glow discharge space circumscribed by the cylindricalsubstrate holders can be established in the reaction chamber 100. Inorder to establish such glow discharge space, the number of thecylindrical substrate holder to be arranged in the reaction chamber 100is desired to be at least four.

[0161] The heater 104 installed in each rotatable cylindrical substrateholder may be an appropriate heater which can be hermetically installedin the cylindrical substrate holder. Such heater can include electricinsulators such as sheathed heater, plate-like heater, and ceramicheater, heat radiators such as halogen lamp, and heat generators bymeans of a vapor or liquid heat exchanging medium. Alternatively, thesesubstrate-heating means may be disposed in a substrate-heating vesselprovided separately from the reaction chamber 100. In this case, it ispossible that the substrates is heated to a desired temperature in thesubstrate-heating vessel, followed by transferring into the reactionchamber 100 under vacuum condition. Further, it is possible to adoptboth the substrate-heating vessel and the heaters 104 installed in thecylindrical substrate holders.

[0162] Herein, for the substrate temperature in the film formation inthe reaction chamber 100, it should be properly determined dependingupon the kind of a deposited film to be formed. However, in general, itis preferably in the range of from 20 to 500° C., more preferably in therange of from 50 to 480° C., most preferably in the range of from 100 to450° C.

[0163] The high frequency power introduction means 102 comprises any ofthe foregoing high frequency power introduction means according to thepresent invention and it is positioned at a central position in thedischarge space 103 and which is electrically connected to the highfrequency power source 107 through a matching box 106.

[0164] Reference numeral 105 indicates a raw material introduction means(comprising four gas feed pipes) connected to a raw material gas supplysystem (not shown) containing gas reservoirs (not shown). For the numberof the gas feed pipe in the raw material gas introduction means 105, itmay be one. However, it is desired to be a number corresponding to about½ of the number of the cylindrical substrates used.

[0165] In the case where a high frequency power introduction means ofthe configuration shown in FIG. 4 which can serves also as a rawmaterial gas introduction means is used as the high frequency powerintroduction means 102, the raw material gas introduction means 105 canbe omitted because said high frequency power introduction means servesalso as the raw material gas introduction means. In this case, aplurality of high frequency power introduction means of theconfiguration shown in FIG. 4 may be spacedly arranged on acircumference concentric to the arrangement circle of the cylindricalsubstrates 101 as previously described.

[0166] In FIGS. 9(a) and 9(b), there is shown only one high frequencypower introduction means. This is not restrictive. The number of thehigh frequency power introduction means used in the reaction chamber maybe plural depending upon the situation.

[0167] The matching box 106 may take any constitution as long as it canadequately match the high frequency power source 107 and a loadoccurred. In this case, it is desired to be made so that the matchingcan be automatically conducted. Alternatively, it is possible to be madesuch that the matching is conducted in a manual manner.

[0168] The cylindrical substrate holder may be constituted by anelectrically conductive material selected from the group constituting ofCu, Al, Au, Ag, Pt, Pb, Ni, Co, Fe, Cr, Mo, Ti, stainless steel, andcomposite materials of these.

[0169] For the substrate 101 positioned on each cylindrical substrateholder, to use a electrically conductive substrate shaped in acylindrical form as shown FIGS. 9(a) and 9(b) is suitable particularlyin the production of an electrophotographic light receiving member. Butit may be shaped in other appropriate form such as a plate-like formdepending upon the kind of a device to be produced.

[0170] The substrate 101 may be a substrate shaped in a cylindrical formor other desired form made of an a metal selected from the groupconsisting of Al, Cr, Mo, Au, In, Nb, Ni, Te, V, Ti, Pt, Pb and Fe; analloy selected from the group of alloys of these metals such asstainless steel; or a material selected from the group consisting ofcomposite materials of these.

[0171] Alternatively, the substrate 101 may comprise an insulatingmember having a surface coated by an electrically conductive material onwhich a deposited film is to be formed. The insulating member in thiscase can include alumina ceramics, aluminum nitride, boron nitride,silicon nitride, silicon carbide, beryllium oxide, quartz glass, andpyrex glass, and besides these, synthetic resins such as polycarbonate,polyamide, polyimide, and Teflon (trademark name). In this case, theremaining surface of the insulating member is desired to be also coatedby an electrically conductive material.

[0172] The production of a light receiving member according to thepresent invention using the plasma CVD apparatus shown in FIGS. 9(a) and9(b) may be conducted, for example, in the following manner.

[0173] A well-cleaned cylindrical substrate 101 having a polishedsurface is positioned on each cylindrical substrate holder in thereaction chamber 100. The inside of the reaction chamber 100 isevacuated to a desired high vacuum degree through the exhaust pipe byoperating the vacuuming device (not shown).

[0174] Thereafter, the substrates 101 positioned on the cylindricalsubstrate holders are heated to a desired temperature by means of theheaters 104 while rotating the cylindrical substrate holders. When thetemperature of each substrate becomes stable at this temperature, a rawmaterial gas from the raw material gas supply system (not shown) isintroduced into the reaction chamber 100 through the raw material gasintroduction means 105. In this case, a due care should be made so thatneither sudden gas release nor sudden gas pressure change are occurred.When the flow rate of the raw material introduced into the reactionchamber 100 becomes stable at a desired value, the main valve of theexhaust system (not shown) is controlled while observing the reading ona vacuum gage (not shown) provided in the exhaust system to establish adesired gas pressure (or a desired inner pressure) in the reactionchamber 100.

[0175] When the inner pressure in the reaction chamber 100 becomesstable, the power source 107 is switched on to apply a high frequencypower (with a desired oscillation frequency) of a desired wattage to thehigh frequency power introduction means 102 through the matching box 106to cause glow discharge in the discharge space 103 of the reactionchamber 100. In this case, a matching circuit (not shown) contained inthe matching box 106 is properly adjusted so that a reflected wave isminimized. By this glow discharge caused, the raw material gasintroduced into the reaction chamber 100 is decomposed to cause theformation of a deposited film on each substrate 101. In this case, byrotating each substrate 101 during the film formation by means of thedriving motor 109, the film is uniformly deposited over the entiresurface of the substrate.

[0176] After completing the film formation, the power source is switchedoff, and the introduction of the raw material gas into the reactionchamber 100 is therminated. Then, the inside of the reaction chamber 100is evacuated to a desired vacuum degree in the same manner as abovedescribed.

[0177] In the case where a multi-layered deposited film is intended toform, the above film-forming procedures are repeated. By this, there canbe formed a multi-layered deposited film on each substrate.

[0178] For the inner pressure (or the gas pressure) in the reactionchamber 100 upon the film formation, it should be properly determineddepending upon the kind of a deposited film to be formed. However, ingeneral, it is preferably in the range of from 0.01 to 1000 Pa, morepreferably in the range of from 0.03 to 300 Pa, most preferably in therange of from 0.1 to 100 Pa.

[0179] For the raw material gas used, for instance, in the case offorming an amorphous silicon (a-Si) deposited film, there can be used,for example, gaseous or easily gasifiable silicon hydrides (silanes)such as SiH₄, Si₂H₆, and the like as a Si-supplying raw material gas.

[0180] Besides these, there can be used fluorine-containing siliconcompounds such as gaseous or easily gasifiable fluorine-substitutedsilane derivatives as a Si-supplying raw material gas. Specific examplesof such fluorine-substituted silane derivative are silicon fluoridessuch as SiF₄, Si₂F₆ and the like, fluorine-substituted silicon hydridessuch as SiH₃F , SiH₂F₂, SiHF₃, and the like.

[0181] If necessary, these Si-supplying raw material gases can be usedby diluting with an appropriate dilution gas such as H₂ gas, He gas, Argas, or Ne gas.

[0182] Further, it is possible to use a doping gas capable supplying anatom belonging to group III of the periodic table such as B, Ga, or Inor an atom belonging to group V of the periodic table such as P, As, orSb together with the foregoing Si-supplying raw material gas.Specifically, in the case of using B as a dopant, the doping gas capableof supplying B can include boron hydrides such as B₂H₆ and B₄H₁₀ andboron halides such as BF₃ and BCl₃. In the case of using P as a dopant,the doping gas capable of supplying P can include phosphorous hydridessuch as PH₃ and P₂H₄.

[0183] Separately, for instance, in the case of forming an amorphoussilicon carbide (a-SiC) deposited film, in addition to the foregoingSi-supplying raw material gas, an appropriate C-supplying raw materialgas used. Such C-supplying raw material gas can include gaseous oreasily gasifiable compounds containing carbon atoms (C) and hydrogenatoms (H) as the constituent atoms such as saturated hydrocarbons of 1to 5 carbon atoms, ethylene series hydrocarbons of 2 to 4 carbon atoms,and acetylene series hydrocarbons of 2 to 3 carbon atoms. Specificexamples of the saturated hydrocarbon are methane (CH₄) and ethane(C₂H₆). Specific examples of the ethylene series hydrocarbon areethylene (C₂H₄) and propylene (C₃H₆). Specific examples of the acetyleneseries hydrocarbon are acetylene (C₂H₂) and methyl acetylene (C₃H₄).

[0184] For instance, in the case of forming an amorphous silicon oxide(a-SiC) deposited film, in addition to the foregoing Si-supplying rawmaterial gas, an appropriate gaseous or easily gasifiable C-supplyingraw material gas used. Such O-supplying raw material gas can includeoxygen (O₂), ozone (O₃), nitrogen monoxide (NO), nitrogen dioxide (NO₂),dinitogen oxide (N₂O), dinitogen trioxide (N₂O₃), dinitrogen tetraoxide(N₂O₄), dinitrogen pentoxide (N₂O₅), nitrogen trioxide (NO₃), and lowersiloxanes comprising silicon atoms (Si), oxygen atoms (O) and hydrogenatoms (H) as the constituent atoms such as disiloxane (H₃SiOSiH₃) andtrisiloxane (H₃SiOSiH₂OSiH₃).

[0185] For instance, in the case of forming an amorphous silicon nitride(a-SiN) deposited film, in addition to the foregoing Si-supplying rawmaterial gas, an appropriate gaseous or easily gasifiable N-supplyingraw material gas used. Such N-supplying raw material gas can includenitrogen and nitrogen compounds such as nitrides and azide compounds.Specific examples are nitrogen (N₂), ammonia (NH₃), hydrazine (H₂NNH₂),hydrogen azide (HN₃) and ammonium azide (NH₄N₃). Besides these, nitrogenhalide compounds such as nitrogen trifluoride (F₃N) and nitrogentetrafluoride (F₄N₂) can be used. These can also introduce halogen atoms(X) in addition to the introduction of nitrogen atoms (N).

[0186] FIGS. 22(a) and 22(b) are schematic diagrams illustrating anotherexample of a plasma CVD apparatus capable of forming a deposited film ona plurality of substrates at the same time in which a high frequencypower introduction means according to the present invention can be used.

[0187] The plasma CVD apparatus shown in FIGS. 22(a) and 22(b) comprisesa modification of the plasma CVD apparatus shown in FIGS. 9(a) and 9(b),in which in addition to the high frequency power introduction means 102positioned at the central position of the discharge space in the plasmaCVD apparatus shown in FIGS. 9(a) and 9(b), eight high frequency powerintroduction means 102 (according to the present invention) areinstalled such that they are spacedly arranged on a circumferenceconcentric to the arrangement circle of the eight cylindrical substrateholders at a position outside the arrangement circle of the eightcylindrical substrate holders, and each cylindrical substrate holderhaving an electrically conductive substrate 101 positioned thereon issupported by a shaft 122 with no driving mechanism. In the apparatusshown in FIGS. 22(a) and 22(b), each high frequency power introductionmeans 102 is electrically connected to a high frequency power source(not shown) through a matching box 106.

[0188] In the apparatus shown in FIGS. 22(a) and 22(b), glow dischargeis uniformly generated inside and outside the arrangement circle of theeight cylindrical substrate holders and because of this, it is notnecessary for the substrates 101 positioned on the cylindrical substrateholders to be rotated upon the film formation. But, if necessary, theymay be rotated as in the case of the apparatus shown in FIGS. 9(a) and9(b).

[0189] The film formation using the apparatus shown in FIGS. 22(a) and22(b) may be conducted in the same manner as in the case of theapparatus shown in FIGS. 9(a) and 9(b).

[0190] In the following, the present invention will be described in moredetail with reference to experiments and examples. It should beunderstood that the scope of the present invention is not limited bythese experiments and examples.

[0191] For a case where no description is made for the joining betweenthe insulating material and the electrode in the following experimentsand examples belonging to the present invention, it means that thejoining was conducted by way of chemical plating. It should beunderstood that the joining between the insulating material and theelectrode in the present invention may be conducted by may of otherjoining manner such as thermal spraying, sputtering, brazing, soliddiffusion welding, plasma CVD or vacuum evaporation.

Experiment 1

[0192] In this experiment, as the high frequency power introductionmeans 102 in the plasma CVD apparatus shown in FIGS. 9(a) and 9(b),there was used the high frequency power introduction means shown in FIG.1 having a length of 420 mm according to the present invention.Distribution state of a plasma generated upon glow discharge in thisapparatus was examined by measuring a saturated electron current bymeans of a Langmuir probe. The Langmuir probe was set to the apparatusso that it can be moved under vacuum condition in the reaction chamber100. The measurement of the saturated electron current was conducted forevery 20 mm length in the generatrix direction of the high frequencypower introduction means 102. Glow discharge was conducted underconditions shown in Table 1.

[0193] The measured saturated electron currents are graphically shown inFIG. 10. In FIG. 10, the largest saturated electron current isnormalized to be 1.

[0194] From FIG. 10, the high frequency power introduction means isunderstood to be substantially uniform for plasmas generated in the glowdischarge.

Comparative Experiment 1

[0195] In this comparative experiment, as the high frequency powerintroduction means 102 in the plasma CVD apparatus shown in FIGS. 9(a)and 9(b), there was used a conventional high frequency powerintroduction means similar to the high frequency power introductionmeans shown in FIG. 1 in terms of the structure but comprising a solidmetal electrode with a ceramic cover and having a clearance of about 1mm between the solid metal electrode and the ceramic cover. Theclearance herein is of a value in the apparatus designing but does notmean that the actual clearance between the solid metal electrode and theceramic cover is uniform at about 1 mm.

[0196] Distribution state of a plasma generated upon glow discharge inthis apparatus was examined in the same manner as in Experiment 1.

[0197] The measured saturated electron currents are graphically shown inFIG. 11. In FIG. 11, the largest saturated electron current isnormalized to be 1.

[0198] From FIG. 11, the conventional high frequency power introductionmeans is understood to be apparently uneven for plasmas generated in theglow discharge.

Experiment 2 and Comparative Experiment 2

[0199] Experiment 2

[0200] In this experiment, as the high frequency power introductionmeans 102 in the plasma CVD apparatus shown in FIGS. 9(a) and 9(b),there was used the high frequency power introduction means shown in FIG.1 having a length of 420 mm according to the present invention.Distribution state of a plasma generated upon glow discharge in thisapparatus was examined by measuring a saturated electron current bymeans of a Langmuir probe. In addition, deposition rate for a filmdeposited was also measured by means of the Langmuir probe. The Langmuirprobe was set to the apparatus so that it can be moved under vacuumcondition in the reaction chamber 100. The measurement of the saturatedelectron current was conducted for every 20 mm length in the generatrixdirection of the high frequency power introduction means 102. Glowdischarge was conducted under conditions shown in Table 2.

Comparative Experiment 2

[0201] In this comparative experiment, as the high frequency powerintroduction means 102 in the plasma CVD apparatus shown in FIGS. 9(a)and 9(b), there were used a plurality of conventional high frequencypower introduction means similar to the high frequency powerintroduction means shown in FIG. 1 in terms of the structure but eachcomprising a solid metal electrode with a ceramic cover and having adifferent clearance in the range of from about 0.2 mm to 20 mm betweenthe solid metal electrode and the ceramic cover. The clearance herein isof a value in the apparatus designing but does not mean that the actualclearance between the solid metal electrode and the ceramic cover isuniform at said value.

[0202] Distribution state of a plasma generated upon glow discharge anddeposition rate for a film deposited were examined in the same manner asin Experiment 2.

Evaluation

[0203] The measured saturated electron currents in Experiment 2 andComparative Experiment 2 are graphically shown in FIG. 12. Each of thevalues shown in FIG. 12 is a ratio of the smallest saturated electroncurrent to the largest saturated electron current (the case wherein nounevenness was observed is 1). The measured deposition rates inExperiment 2 and Comparative Experiment 2 are graphically shown in FIG.13. The deposition rates shown in FIG. 13 are values relative to thedeposition rate obtained in the case of 0.2 mm in the foregoingclearance, which is set at 1.

[0204] Based on the results shown in FIGS. 12 and 13, the followingfacts are understood. In the case of using the conventional highfrequency power introduction means having a clearance between theelectrode and the cover, there is occurred a distinguishable unevennessin a saturated electron current distribution. The occurrent of thisunevenness is liable to relax as the magnitude of the clearance isenlarged. However, there is still occurred an undesirable unevenness ina saturated electron current distribution when the magnitude of theclearance is 20 mm.

[0205] For the deposition rate in the case of using the conventionalhigh frequency power introduction means, it has a tendency of decreasingas the magnitude of the clearance is increased. This tendency issignificant when the magnitude of the clearance is more than 10 mm. Thereason for this is considered such that the loss in the high frequencypower is increased as the magnitude of the clearance is increased andparticularly, said loss is markedly increased when the magnitude of theclearance is more than 10 mm.

Experiment 3 and Comparative Experiments 3 and 4 Experiment 3

[0206] In this experiment, there were prepared eight light receivingmembers of the configuration shown in FIG. 14. In FIG. 14, referencenumeral 1001 indicates a light receiving member comprising a chargeinjection inhibition layer 1003, a photoconductive layer 1004 and asurface layer 1005 stacked in the named order on a substrate 1002.

[0207] Particularly, using the plasma CVD apparatus shown in FIGS. 9(a)and 9(b) having the high frequency power introduction means shown inFIG. 1 according to the present invention, there were prepared saideight light receiving members in accordance with the previouslydescribed film-forming procedures using the plasma CVD apparatus shownin FIGS. 9(a) and 9(b) and under film-forming conditions shown in Table3. It should be noted that the thicknesses mentioned in Table 3 arerough values.

[0208] Herein, the charge injection inhibition layer is composed of anamorphous material containing silicon atoms (Si) as a matrix, hydrogenatoms (H) and boron atoms (B), the photoconductive layer is composed ofan amorphous material containing silicon atoms (Si) as a matrix,hydrogen atoms (H) and boron atoms (B), and the surface layer iscomposed of an amorphous material containing silicon atoms (Si), carbonatoms (C) and hydrogen atoms (H).

[0209] In this experiment, as the high frequency power introductionmeans, there were used a plurality of high frequency power introductionmeans of the configuration shown in FIG. 1 each comprising an electrode112 having an alumina ceramic material as an insulating material 111plasma-sprayed on the surface of the electrode in which the insulatingmaterial 111 has a sandblasted uneven surface (on the glow dischargezone side) of a different surface roughness in the range of from about 1μm to about 300 μm in terms of JIS ten-point average roughness (RZ). Andthe above fim formation for the preparation of the eight light receivingmembers was conducted for each of these high frequency powerintroduction means.

[0210] For the eight light receiving members obtained in each lot, theirsurfaces were observed using an optical microscope, wherein the numberof a spherical growth defect of more than 10 um in diameter present per10 cm² was examined. And there was obtained a mean value among thespherical growth defect numbers of the eight light receiving members.

Comparative Experiment 3

[0211] The procedures of Experiment 3 were repeated, except that theplurality of high frequency power introduction means used in Experiment3 were replaced by a plurality of conventional high frequency powerintroduction means each comprising a metal electrode having an aluminaceramic material plasma-sprayed on the surface of the electrode in whichthe insulating material has a sandblasted uneven surface (on the glowdischarge zone side) of a different surface roughness in the range offrom about 1 μm to about 300 μm in terms of JIS ten-point averageroughness (RZ), to thereby obtained eight light receiving members foreach high frequency power introduction means.

[0212] For the eight light receiving members obtained in each lot, theirsurfaces were observed using an optical microscope, wherein the numberof a spherical growth defect of more than 10 um in diameter present per10 cm² was examined. And there was obtained a mean value among thespherical growth defect numbers of the eight light receiving members.

Comparative Experiment 4

[0213] The procedures of Experiment 3 were repeated, except that theplurality of high frequency power introduction means used in Experiment3 were replaced by a plurality of conventional high frequency powerintroduction means each comprising only a metal electrode having noinsulating material cover in which the metal electrode has a sandblasteduneven surface (on the glow discharge zone side) of a different surfaceroughness in the range of from about 1 μm to about 300 μm in terms ofJIS ten-point average roughness (RZ), to thereby obtained eight lightreceiving members for each high frequency power introduction means.

[0214] For the eight light receiving members obtained in each lot, theirsurfaces were observed using an optical microscope, wherein the numberof a spherical growth defect of more than 10 um in diameter present per10 cm² was examined. And there was obtained a mean value among thespherical growth defect numbers of the eight light receiving members.

Evaluation

[0215] The results obtained in Experiment 3 and Comparative Experiments3 and 4 are graphically shown in FIG. 15.

[0216] The spherical growth defect values in FIG. 15 are values relativeto the spherical growth defect value obtained in the case of about 30 umin surface roughness in Experiment 3, which is set at 1.

[0217] Based on the results shown in FIG. 15, the following facts areunderstood.

[0218] In the case of using a high frequency power introduction meanshaving a roughened surface, there is a tendency in that layer peeling isprevented from occurring and the occurrence of a spherical growth defectis diminished. Especially, as apparent from the results obtainedExperiment 3, the use of any of the high frequency power introductionmeans having a surface with such surface roughness as above describedaccording to the present invention provides a significant effect ofmarkedly preventing the occurrence of a spherical growth defect.However, it is relatively difficult to efficiently attain a surfaceroughness of beyond 200 μm. Therefore, for the practically attainablesurface roughness, a preferable range is 200 μm or less, and a morepreferable range is from 5 μm to 200 μm.

[0219] For the high frequency power introduction means (an aluminaceramic material was simply plasma-sprayed) used in ComparativeExperiment 3, the surface of each of their plasma-sprayed bodies wasobserved. As a result, there was found a ruin where a part of theplasma-sprayed body had been removed for all the high frequency powerintroduction means. In addition, there was found that the magnitude forthis removal tends to increase as the surface roughness is increased. Itis considered that the results obtained in Comparative Experiment 3shown in FIG. 15 indicate that the adhesion of a film deposited on thesurface of the high frequency power introduction means is improved byincreasing the surface roughness where the prevention of the occurrenceof a sperical growth defect is expected to improve accordingly, but aninfluence due to the removal of the plasma-sprayed body graduallybecomes significant where the occurrence of a spherical growth defecttends to increase from a certain surface roughness.

[0220] Even for such high frequency power introduction means used inComparative Experiment 4, the situation of preventing the occurrence ofa spherical growth defect is improved by increasing the surfaceroughness. But the effect is apparently inferior to that in the case ofusing the high frequency power introduction means according to thepresent invention.

Experiment 4

[0221] In this experiment, as the high frequency power introductionmeans 102 in the plasma CVD apparatus shown in FIGS. 9(a) and 9(b),there was used the high frequency power introduction means shown in FIG.5 (in which the insulating material 111 comprises an alumina ceramicmaterial) having a length of 420 mm according to the present invention.Distribution state of a plasma generated upon glow discharge in thisapparatus was examined by measuring a saturated electron current bymeans of a Langmuir probe. The Langmuir probe was set to the apparatusso that it can be moved under vacuum condition in the reaction chamber100. The measurement of the saturated electron current was conducted forevery 20 mm length in the generatrix direction of the high frequencypower introduction means 102. Glow discharge was conducted underconditions shown in Table 4.

[0222] The measured saturated electron currents are graphically shown inFIG. 16. In FIG. 16, the largest saturated electron current isnormalized to be 1.

[0223] From FIG. 16, the high frequency power introduction means isunderstood to be substantially uniform for plasmas generated in the glowdischarge.

Comparative Experiment 5

[0224] In this comparative experiment, as the high frequency powerintroduction means 102 in the plasma CVD apparatus shown in FIGS. 9(a)and 9(b), there was used a high frequency power introduction meanscomprising a solid cylindrical metal electrode (having a size which isthe same as the outer diameter of the electrode 112 (that is, the innerdiameter of the insulating material 111 in other words) of the highfrequency power introduction means used in Experiment 4) with noimpedance discontinueing pattern.

[0225] Distribution state of a plasma generated upon glow discharge inthis apparatus was examined in the same manner as in Experiment 4.

[0226] The measured saturated electron currents are graphically shown inFIG. 17. In FIG. 17, the largest saturated electron current isnormalized to be 1.

[0227] From FIG. 17, the high frequency power introduction means used inthis comparative example is understood to be apparently uneven forplasmas generated in the glow discharge.

Comparative Experiment 6

[0228] In this comparative experiment, as the high frequency powerintroduction means 102 in the plasma CVD apparatus shown in FIGS. 9(a)and 9(b), there was used a high frequency power introduction meanscomprising a modification of the high frequency power introduction meansused in Experiment 4 such that the insulating material 111 is omitted.

[0229] Distribution state of a plasma generated upon glow discharge inthis apparatus was examined in the same manner as in Experiment 4.

[0230] The measured saturated electron currents are graphically shown inFIG. 18. In FIG. 18, the largest saturated electron current isnormalized to be 1.

[0231] From FIG. 18, the high frequency power introduction means used inthis comparative example is understood to be apparently uneven forplasmas generated in the glow discharge.

Comparative Experiment 7

[0232] In this comparative experiment, as the high frequency powerintroduction means 102 in the plasma CVD apparatus shown in FIGS. 9(a)and 9(b), there was used a high frequency power introduction meanscomprising a modification of the high frequency power introduction meansused in Experiment 4 such that a clearance of about 0.5 mm is providedbetween the insulating material 111 and the electrode 112.

[0233] Distribution state of a plasma generated upon glow discharge inthis apparatus was examined in the same manner as in Experiment 4.

[0234] The measured saturated electron currents are graphically shown inFIG. 19. In FIG. 19, the largest saturated electron current isnormalized to be 1.

[0235] From FIG. 19, the high frequency power introduction means used inthis comparative example is understood to be apparently uneven forplasmas generated in the glow discharge.

Experiment 5 and Comparative Experiments 8 and 9

[0236] Experiment 5

[0237] In this experiment, there were prepared eight light receivingmembers of the configuration shown in FIG. 20. In FIG. 20, referencenumeral 1001 indicates a light receiving member comprising a chargeinjection inhibition layer 1003, a photoconductive layer 1004 and asurface layer 1005 stacked in the named order on a substrate 1002.

[0238] Particularly, using the plasma CVD apparatus shown in FIGS. 9(a)and 9(b) having the high frequency power introduction means shown inFIG. 5 according to the present invention, there were prepared saideight light receiving members in accordance with the previouslydescribed film-forming procedures using the plasma CVD apparatus shownin FIGS. 9(a) and 9(b) and under film-forming conditions shown in Table5. It should be noted that the thicknesses mentioned in Table 3 arerough values.

[0239] Herein, the charge injection inhibition layer is composed of anamorphous material containing silicon atoms (Si) as a matrix, hydrogenatoms (H) and boron atoms (B), the photoconductive layer is composed ofan amorphous material containing silicon atoms (Si) as a matrix,hydrogen atoms (H) and boron atoms (B), and the surface layer iscomposed of an amorphous material containing silicon atoms (Si), carbonatoms (C) and hydrogen atoms (H).

[0240] In this experiment, as the high frequency power introductionmeans, there were used a plurality of high frequency power introductionmeans of the configuration shown in FIG. 5 each comprising an electrode112 (with an impedance discontinueing pattern) having an alumina ceramicmaterial as an insulating material 111 plasma-sprayed to the surface ofthe electrode 112 in a state with no clearance in which the insulatingmaterial 111 has a sandblasted uneven surface (on the glow dischargezone side) of a different surface roughness in the range of from about 1μm to about 200 μm in terms of JIS ten-point average roughness (RZ). Andthe above film formation for the preparation of the eight lightreceiving members was conducted for each of these high frequency powerintroduction means.

[0241] For the eight light receiving members obtained in each lot, theirsurfaces were observed using an optical microscope, wherein the numberof a spherical growth defect of more than 10 um in diameter present per10 cm² was examined. And there was obtained a mean value among thespherical growth defect numbers of the eight light receiving members.

Comparative Example 8

[0242] The procedures of Experiment 5 were repeated, except that theplurality of high frequency power introduction means used in Experiment5 were replaced by a plurality of high frequency power introductionmeans each comprising a metal electrode (with no impedancediscontinueing pattern) having an alumina ceramic material (comprisingalumina ceramic material particles of a given mean particle size)plasma-sprayed on the surface of the electrode in which the insulatingmaterial has an uneven surface (on the glow discharge zone side) with adifferent surface roughness (due to the difference in the mean particlesize of the alumina ceramic material particles used) in the range offrom about 1 μm to about 200 μm in terms of JIS ten-point averageroughness (RZ), to thereby obtained eight light receiving members foreach high frequency power introduction means.

[0243] For the eight light receiving members obtained in each lot, theirsurfaces were observed using an optical microscope, wherein the numberof a spherical growth defect of more than 10 μm in diameter present per10 cm² was examined. And there was obtained a mean value among thespherical growth defect numbers of the eight light receiving members.

Comparative Example 9

[0244] The procedures of Experiment 5 were repeated, except that theplurality of high frequency power introduction means used in Experiment5 were replaced by a plurality of high frequency power introductionmeans each comprising only a metal electrode (with no impedancediscontinueing pattern) having no insulating material cover in which themetal electrode has a sandblasted uneven surface (on the glow dischargezone side) of a different surface roughness in the range of from about 1μm to about 300 μm in terms of JIS ten-point average roughness (RZ), tothereby obtained eight light receiving members for each high frequencypower introduction means.

[0245] For the eight light receiving members obtained in each lot, theirsurfaces were observed using an optical microscope, wherein the numberof a spherical growth defect of more than 10 μm in diameter present per10 cm² was examined. And there was obtained a mean value among thespherical growth defect numbers of the eight light receiving members.

Evaluation

[0246] The results obtained in Experiment 5 and Comparative Examples 8and 9 are graphically shown in FIG. 21.

[0247] The spherical growth defect values in FIG. 21 are values relativeto the spherical growth defect value obtained in the case of about 28 μmin surface roughness in Experiment 5, which is set at 1.

[0248] Based on the results shown in FIG. 21, the following facts areunderstood.

[0249] In the case of using a high frequency power introduction meanshaving a roughened surface, there is a tendency in that layer peeling isprevented from occurring and the occurrence of a spherical growth defectis diminished. Especially, as apparent from the results obtainedExperiment 5, the use of any of the high frequency power introductionmeans (having the configuration shown in FIG. 5) having a surface withsuch surface roughness as above described according to the presentinvention provides a significant effect of markedly preventing theoccurrence of a spherical growth defect.

[0250] For the high frequency power introduction means (an aluminaceramic material was simply plasma-sprayed to a metal electrode with noimpedance discontinueing pattern) used in Comparative Experiment 8,there is a tendency in that the occurrence of a spherical defect isdecreased as the surface roughness is increased to a certain magnitudebut when the surface roughness is further increased beyond saidmagnitude, the occurrence of a spherical defect is increasedaccordingly. The reason for this is considered such that the adhesion ofthe plasma-sprayed body with the electrode is weakened as the surfaceroughness is increased where the plasma-sprayed body is partly peeledfrom the electrode. Further, in each of Comparative Examples 8 and 9,there was observed the occurrence of sparking during the glow discharge.

Experiment 6

[0251] In this experiment, there were prepared a plurality of lots eachcomprising eight light receiving members of the configuration shown inFIG. 20 comprising a charge injection inhibition layer 1003, aphotoconductive layer 1004 and a surface layer 1005 stacked in the namedorder on a substrate 1002.

[0252] Particularly, using the plasma CVD apparatus shown in FIGS. 9(a)and 9(b) having the high frequency power introduction means shown inFIG. 5 (comprising a metallic electrode 112 with an impedancediscontinueing pattern and a titanium dioxide material as an insulatingmaterial 111 plasma-sprayed to the surface of the electrode 112 in astate with no clearance) according to the present invention, each lotcomprising eight light receiving members was prepared in accordance withthe previously described film-forming procedures using the plasma CVDapparatus shown in FIGS. 9(a) and 9(b) and under film-forming conditionsshown in Table 6 wherein a high frequency power with an oscillationfrequency of 105 MHz was used and the wattage thereof was varied in therange of from 500 W to 5000 W in the formation of the photoconductivelayer in each case. It should be noted that the thicknesses mentioned inTable 6 are rough values.

Evaluation

[0253] For the light receiving members obtained in each lot, evaluationwas conducted with respect to occurrence of spherical growth defect intheir surface, occurrence of uneven image density in the imagereproduction, and occurrence of black dot in the image reproduction inthe following manner. The evaluated results obtained are collectivelyshown in Table 7.

[0254] (1) Evaluation of the Spherical Growth Defect

[0255] For the eight light receiving members obtained in each lot, theirsurfaces were observed using an optical microscope, wherein the numberof a spherical growth defect of more than 10 μm in diameter present per10 cm² was examined. And there was obtained a mean value among thespherical growth defect numbers of the eight light receiving members.

[0256] The means value obtained for each lot is shown in Table 7 as avalue relative to the mean value obtained for the lot in which thewattage of the high frequency power was made to be 1500 W, which is setat 1.

[0257] (2) Evaluation of the Occurrence of Uneven Image Density

[0258] For the eight light receiving members obtained in each lot, theevaluation of the occurrence of uneven image density was conducted asfollows. Each light receiving member was set to an electrophotographicapparatus NP 6060 modified to be usable for experimental purposes(produced by CANON Kabushiki Kaisha), wherein using a halftone testchart FY9-9042 (produced by CANON Kabushiki Kaisha) as an original,copying shot for an A3-sized paper was conducted to obtain a copy. Forthe resultant copy, the image density (in terms of optical density) ateach of 50 points (areas) randomly selected on the copy was measured bymeans of a reflection densitometer (produced by Macbeth Company). Forthe 50 image density values thus measured, a ratio of the minimum imagedensity value to the maximum image density value was obtained. And therewas obtained a mean value among the eight ratios (of the minimum imagedensity value/the maximum image density value) obtained for the eightlight receiving members in each lot. The means value obtained was madeto be an uneven image density for the eight light receiving members ineach lot.

[0259] The uneven image density value obtained for each lot is shown inTable 7 as a value relative to the uneven image density value obtainedfor the lot in which the wattage of the high frequency power was made tobe 1500 W, which is set at 1.

[0260] (3) Evaluation of the Occurrence of Black Dot

[0261] For the eight light receiving members obtained in each lot, theevaluation of the occurrence of black dot was conducted as follows. Eachlight receiving member was set to the foregoing electrophotographicapparatus NP 6060 (produced by CANON Kabushiki Kaisha), wherein using ahalftone test chart FY9-9042 (produced by CANON Kabushiki Kaisha) as anoriginal, copying shot for an A3-sized paper was conducted 3000000 timesduring which after every 10000 copying shots, a white pater (instead ofthe halftone test chart) was subjected to copying shot. In this way,there were obtained copies from the white papers as the original for theeight light receiving members in each lot.

[0262] For the resultant copies from the white paters as the original,evaluation was conducted with respect to black dot occurrence.

[0263] The evaluated results obtained for each lot are collectivelyshown in Table 7 on the basis of the following criteria.

[0264] ⊙: a case where no black dot is observed in all the copies,

[0265] ◯: a case where no distinguishable black dot is observed in allthe copies,

[0266] Δ: a case where a few distinguishable black dots are observed inat least one of the copies but these black dots are not such that makeminute lines or the like obscure and therefore, are not practicallyproblematic, and

[0267] X : a case where apparent black dots which make minute lines orthe like apparently obsure are observed in at least one of the copiesand therefore, they are problematic in practice.

[0268] From the results shown in Table 7, it is understood that all thelight receiving members are quite satisfactory for all the evaluationitems.

Comparative Experiment 10

[0269] The procedures of Experiment 6 were repeated, except that thehigh frequency power introduction means shown in FIG. 5 used inExperiment 6 was replaced by a high frequency power introduction meanscomprising a modification of the high frequency power introduction meansshown in FIG. 5 such that the electrode has no impedance discontinueingpattern, to thereby obtain a plurality of lots each comprising eightlight receiving members of the configuration shown in FIG. 20.

[0270] For the resultant light receiving members, evaluation wasconducted with respect to occurrence of spherical growth defect in theirsurface, occurrence of uneven image density in the image reproduction,and occurrence of black dot in the image reproduction in the same manneras in Experiment 6. The evaluated results obtained are collectivelyshown in Table 8. Each of the evaluated values for the uneven imagedensity and the number of a spherical growth defect shown Table 8 is avalue relative to the corresponding evaluated value in Experiment 6where the wattage of the high frequency power was made to be 1500 W,which is set at 1.

[0271] Based on the results obtained, there was obtained a finding thatthe high frequency power introduction means used in this comparativeexperiment has a tendency in that as the wattage of the high frequencypower is increased, the situation for uneven image density to beoccurred is improved but the black dot occurrence is slightly increased.For the reason why the black dot occurrence is slightly increased as thewattage of the high frequency power is increased, it is considered suchthat the irradiation of the high frequency power is somewhat localizedand because of this, the high frequency power is partly converged toinfluence to the growth of a film deposited.

Comparative Experiment 11

[0272] The procedures of Experiment 6 were repeated, except that thehigh frequency power introduction means shown in FIG. 5 used inExperiment 6 was replaced by a high frequency power introduction meanscomprising a modification of the high frequency power introduction meansshown in FIG. 5 such that the insulating material is omitted, to therebyobtain a plurality of lots each comprising eight light receiving membersof the configuration shown in FIG. 20.

[0273] For the resultant light receiving members, evaluation wasconducted with respect to occurrence of spherical growth defect in theirsurface, occurrence of uneven image density in the image reproduction,and occurrence of black dot in the image reproduction in the same manneras in Experiment 6. The evaluated results obtained are collectivelyshown in Table 9. Each of the evaluated values for the uneven imagedensity and the number of a spherical growth defect shown Table 9 is avalue relative to the corresponding evaluated value in Experiment 6where the wattage of the high frequency power was made to be 1500 W,which is set at 1.

[0274] Based on the results obtained, there was obtained a finding thatthe high frequency power introduction means used in this comparativeexperiment has a tendency of not providing a desirable effect of theimpedance discontinueing pattern present at the electrode at such extentas in Experiment 6. In addition, as apparent from Table 9, it isunderstood that the high frequency power introduction means used in thiscomparative experiment causes a relatively large number of sphericalgrowth defects due to peeling of the film deposited thereon.

Experiment 7

[0275] In this experiment, there were prepared a plurality of lots eachcomprising eight light receiving members of the configuration shown inFIG. 20 comprising a charge injection inhibition layer 1003, aphotoconductive layer 1004 and a surface layer 1005 stacked in the namedorder on a substrate 1002.

[0276] Particularly, using the plasma CVD apparatus shown in FIGS. 9(a)and 9(b) having the high frequency power introduction means shown inFIG. 5 (comprising a metallic electrode 112 with an impedancediscontinueing pattern and an aluminum nitride material as an insulatingmaterial 111 plasma-sprayed to the surface of the electrode 112 in astate with no clearance) according to the present invention, each lotcomprising eight light receiving members was prepared in accordance withthe previously described film-forming procedures using the plasma CVDapparatus shown in FIGS. 9(a) and 9(b) and under film-forming conditionsshown in Table 10 wherein a high frequency power with a differenyoscillation frequency of 13.56 MHz, 20 MHz, 60 MHz, 105 MHz, 450 MHz or800 MHz was used in each case (see, Table 11). It should be noted thatthe thicknesses mentioned in Table 10 are rough values.

[0277] For the resultant light receiving members, evaluation wasconducted with respect to occurrence of spherical growth defect in theirsurface, occurrence of uneven image density in the image reproduction,and occurrence of black dot in the image reproduction in the same manneras in Experiment 6. The evaluated results obtained are collectivelyshown in Table 11.

[0278] The mark “X” in Table 11 indicates that glow discharge could notbe stably maintained under the condition of 13. 56 MHz in oscillationfrequency and therefore, no light receiving member could not beprepared.

[0279] Based on the results shown in Table 11, it is understood that thelight receiving members obtained using a high frequency power with anoscillation frequency in the range of 20 MHz to 450 MHz are quitesatisfactory for all the evaluation items. In the case where a highfrequency power with an oscillation frequency of 800 MHz was used,though glow discharge could be stably maintained, the matchingconditions for the high frequency power could not be stabilized. This isconsidered to a reason why the light receiving members obtained in thiscase cased a relatively large uneven image density.

[0280] In the following, the present invention will be further describedwith reference to examples, which are only for illustrative purposes andare not intended to restrict the scope of the present invention.

EXAMPLE 1

[0281] In this example, there were prepared eight light receivingmembers of the configuration shown in FIG. 14.

[0282] Particularly, using the plasma CVD apparatus shown in FIGS. 9(a)and 9(b) having the high frequency power introduction means shown inFIG. 1 according to the present invention, there were prepared saideight light receiving members in accordance with the previouslydescribed film-forming procedures using the plasma CVD apparatus shownin FIGS. 9(a) and 9(b) and under film-forming conditions shown in Table12. It should be noted that the thicknesses mentioned in Table 12 arerough values.

Evaluation

[0283] For the resultant eight light receiving members, evaluation wasconducted with respect to occurrence of spherical growth defect in theirsurface, unevenness in layer thickness, and occurrence of uneven imagedensity in the image reproduction in the following manner. The evaluatedresults obtained are collectively shown in Table 13.

[0284] (1) Evaluation of the Spherical Growth Defect

[0285] This evaluation was conducted in the same manner as in Experiment6.

[0286] The evaluated result obtained is shown in Table 13.

[0287] (2) Evaluation of the Unevenness in Layer Thickness

[0288] For each of the eight light receiving members, the layerthickness at each of 17 points selected at an interval of 2 cm in thegeneratrix direction of the light receiving member was measured by meansof an eddy current type thickness measuring instrument. For the measuredresults for each measured point of the eight light receiving members,there was obtained a mean value, wherein there were obtained 17 meanvalues. And of the resultant 17 mean values, a ratio of the minimum meanvalue to the maximum mean value was obtained. The resultant ratio wasmade to be an unevenness in layer thickness. The result is shown inTable 13.

[0289] (3) Evaluation of the Occurrence of Uneven Image Density

[0290] This evaluation was conducted in the same manner as in Experiment6.

[0291] The evaluated result obtained is shown in Table 13.

Comparative Example 1

[0292] The procedures of Example 1 were repeated, except that the highfrequency power introduction means used in Example 1 was replaced by ahigh frequency power introduction means comprising a solid metalelectrode with a ceramic cover and having a clearance of about 0.5 mm(this clearance is a value in the apparatus designing but does not meanthat the actual clearance between the solid metal electrode and theceramic cover is uniform at said value), to thereby obtained eight lightreceiving members.

[0293] For the resultant eight light receiving members, evaluation wasconducted with respect to occurrence of spherical growth defect in theirsurface, unevenness in layer thickness, and occurrence of uneven imagedensity in the image reproduction in the same manner as in Example 1.The evaluated results obtained are collectively shown in Table 13.

Comparative Example 2

[0294] The procedures of Example 1 were repeated, except that the highfrequency power introduction means used in Example 1 was replaced by ahigh frequency power introduction means comprising a solid metalelectrode and an alumina ceramic coated on the surface of the solidmetal electrode by means of plasma-spraying, to thereby obtained eightlight receiving members.

[0295] For the resultant eight light receiving members, evaluation wasconducted with respect to occurrence of spherical growth defect in theirsurface, unevenness in layer thickness, and occurrence of uneven imagedensity in the image reproduction in the same manner as in Example 1.The evaluated results obtained are collectively shown in Table 13.

Total Evaluation

[0296] Each of the evaluated values for Comparative Examples 1 and 2shown in Table 13 is a value relative to the corresponding evaluatedvalue in Example 1, which is set at 1.

[0297] From the results shown in Table 13, the following facts areunderstood. Comparative Example 1 is apparently inferior to Example 1with respect to the unevenness in layer thickness and the occurrence ofuneven image density. Comparative 2 is inferior to Example 1 withrespect to the number of a spherical growth defect occurred, though theformer is similar to the latter with respect to the unevenness in layerthickness and the occurrence of uneven image density.

EXAMPLE 2

[0298] In this example, there were prepared a plurality of lots eachcomprising eight light receiving members of the configuration shown inFIG. 14.

[0299] Particularly, using the plasma CVD apparatus shown in FIGS. 9(a)and 9(b) having the high frequency power introduction means shown inFIG. 1 according to the present invention, each lot comprising eightlight receiving members was prepared in accordance with the previouslydescribed film-forming procedures using the plasma CVD apparatus shownin FIGS. 9(a) and 9(b) and under film-forming conditions shown in Table14 wherein a high frequency power with a different oscillation frequencyof 20 MHz, 50 MHz, 105 MHz, 200 MHz or 450 MHz (see, Table 15) was usedin each case. It should be noted that the thicknesses mentioned in Table14 are rough values.

[0300] For the light receiving members obtained in each lot, evaluationwas conducted with respect to occurrence of spherical growth defect intheir surface, unevenness in layer thickness, and occurrence of unevenimage density in the image reproduction in the same manner as inExample 1. The evaluated results obtained are collectively shown inTable 15.

[0301] Each of the valuated values obtained for each lot shown in Table15 is a value relative to the corresponding evaluated value obtained forthe lot in which the oscillation frequency of 105 MHz was used, which isset at 1.

[0302] Based on the results shown in Table 15, it is understood that thelight receiving members obtained using a high frequency power with anoscillation frequency in the range of 20 MHz to 450 MHz are quitesatisfactory for all the evaluation items.

EXAMPLE 3

[0303] In this example, there were prepared a plurality of lots eachcomprising eight light receiving members of the configuration shown inFIG. 14.

[0304] Particularly, using the plasma CVD apparatus shown in FIGS. 9(a)and 9(b) having the high frequency power introduction means shown inFIG. 2 (having the metal bar 115 disposed in the cavity of the electrode112) according to the present invention, each lot comprising eight lightreceiving members was prepared in accordance with the previouslydescribed film-forming procedures using the plasma CVD apparatus shownin FIGS. 9(a) and 9(b) and under film-forming conditions shown in Table16 wherein a high frequency power with a different oscillation frequencyof 20 MHz, 50 MHz, 105 MHz, 200 MHz or 450 MHz (see, Table 17) was usedin each case. It should be noted that the thicknesses mentioned in Table16 are rough values.

[0305] For the light receiving members obtained in each lot, evaluationwas conducted with respect to occurrence of spherical growth defect intheir surface, unevenness in layer thickness, and occurrence of unevenimage density in the image reproduction in the same manner as inExample 1. The evaluated results obtained are collectively shown inTable 17.

[0306] Each of the valuated values obtained for each lot shown in Table17 is a value relative to the corresponding evaluated value obtained forthe lot in Example 2 in which the oscillation frequency of 105 MHz wasused, which is set at 1.

[0307] Based on the results shown in Table 17, it is understood that thelight receiving members obtained using a high frequency power with anoscillation frequency in the range of 20 MHz to 450 MHz are quitesatisfactory for all the evaluation items.

EXAMPLE 4

[0308] In this example, there were prepared a plurality of lots eachcomprising eight light receiving members of the configuration shown inFIG. 14.

[0309] Particularly, using the plasma CVD apparatus shown in FIGS. 9(a)and 9(b) having the high frequency power introduction means shown inFIG. 3 (provided with the cooling mechanism) according to the presentinvention, each lot comprising eight light receiving members wasprepared in accordance with the previously described film-formingprocedures using the plasma CVD apparatus shown in FIGS. 9(a) and 9(b)and under film-forming conditions shown in Table 18 wherein a highfrequency power with a different oscillation frequency of 20 MHz, 50MHz, 105 MHz, 200 MHz or 450 MHz (see, Table 19) was used in each case.It should be noted that the thicknesses mentioned in Table 18 are roughvalues.

[0310] For the light receiving members obtained in each lot, evaluationwas conducted with respect to occurrence of spherical growth defect intheir surface, unevenness in layer thickness, and occurrence of unevenimage density in the image reproduction in the same manner as inExample 1. The evaluated results obtained are collectively shown inTable 19.

[0311] Each of the valuated values obtained for each lot shown in Table19 is a value relative to the corresponding evaluated value obtained forthe lot in Example 2 in which the oscillation frequency of 105 MHz wasused, which is set at 1.

[0312] Based on the results shown in Table 19, it is understood that thelight receiving members obtained using a high frequency power with anoscillation frequency in the range of 20 MHz to 450 MHz are quitesatisfactory for all the evaluation items.

EXAMPLE 5

[0313] In this example, there were prepared a plurality of lots eachcomprising eight light receiving members of the configuration shown inFIG. 14.

[0314] Particularly, using the plasma CVD apparatus shown in FIGS. 9(a)and 9(b) having the high frequency power introduction means shown inFIG. 3 (in which the cooling mechanism is changed into a heatingmechanism using a heating medium) according to the present invention,each lot comprising eight light receiving members was prepared inaccordance with the previously described film-forming procedures usingthe plasma CVD apparatus shown in FIGS. 9(a) and 9(b) and underfilm-forming conditions shown in Table 20 wherein a high frequency powerwith a different oscillation frequency of 20 MHz, 50 MHz, 105 MHz, 200MHz or 450 MHz (see, Table 21) was used in each case. It should be notedthat the thicknesses mentioned in Table 20 are rough values.

[0315] For the light receiving members obtained in each lot, evaluationwas conducted with respect to occurrence of spherical growth defect intheir surface, unevenness in layer thickness, and occurrence of unevenimage density in the image reproduction in the same manner as inExample 1. The evaluated results obtained are collectively shown inTable 21.

[0316] Each of the valuated values obtained for each lot shown in Table21 is a value relative to the corresponding evaluated value obtained forthe lot in Example 2 in which the oscillation frequency of 105 MHz wasused, which is set at 1.

[0317] Based on the results shown in Table 21, it is understood that thelight receiving members obtained using a high frequency power with anoscillation frequency in the range of 20 MHz to 450 MHz are quitesatisfactory for all the evaluation items.

EXAMPLE 6

[0318] In this example, there were prepared a plurality of lots eachcomprising eight light receiving members of the configuration shown inFIG. 14.

[0319] Particularly, using the plasma CVD apparatus shown in FIGS. 9(a)and 9(b) having the high frequency power introduction means shown inFIG. 4 (provided with the raw material gas introduction mechanism)according to the present invention, each lot comprising eight lightreceiving members was prepared in accordance with the previouslydescribed film-forming procedures using the plasma CVD apparatus shownin FIGS. 9(a) and 9(b) and under film-forming conditions shown in Table22 wherein a high frequency power with a different oscillation frequencyof 20 MHz, 50 MHz, 105 MHz, 200 MHz or 450 MHz (see, Table 23) was usedin each case. It should be noted that the thicknesses mentioned in Table22 are rough values.

[0320] For the light receiving members obtained in each lot, evaluationwas conducted with respect to occurrence of spherical growth defect intheir surface, unevenness in layer thickness, and occurrence of unevenimage density in the image reproduction in the same manner as inExample 1. The evaluated results obtained are collectively shown inTable 23.

[0321] Each of the valuated values obtained for each lot shown in Table23 is a value relative to the corresponding evaluated value obtained forthe lot in Example 2 in which the oscillation frequency of 105 MHz wasused, which is set at 1.

[0322] Based on the results shown in Table 23, it is understood that thelight receiving members obtained using a high frequency power with anoscillation frequency in the range of 20 MHz to 450 MHz are quitesatisfactory for all the evaluation items.

EXAMPLE 7

[0323] In this example, there were prepared eight light receivingmembers of the configuration shown in FIG. 20 in the following manner.

[0324] Using the plasma CVD apparatus shown in FIGS. 9(a) and 9(b)having the high frequency power introduction means shown in FIG. 5(comprising the metallic electrode 112 with an impedance discontinueingpattern and an alumina ceramic material as the insulating material 111plasma-sprayed to the surface of the electrode 112 in a state with noclearance) according to the present invention, said eight lightreceiving members were prepared in accordance with the previouslydescribed film-forming procedures using the plasma CVD apparatus shownin FIGS. 9(a) and 9(b) and under film-forming conditions shown in Table24. It should be noted that the thicknesses mentioned in Table 24 arerough values.

[0325] For the resultant light receiving members, evaluation wasconducted with respect to occurrence of spherical growth defect in theirsurface, occurrence of uneven image density in the image reproduction,and occurrence of black dot in the image reproduction in the same manneras in Experiment 6. The evaluated results obtained are collectivelyshown in Table 29.

EXAMPLE 8

[0326] In this example, there were prepared eight light receivingmembers of the configuration shown in FIG. 20 in the following manner.

[0327] Using the plasma CVD apparatus shown in FIGS. 9(a) and 9(b)having the high frequency power introduction means shown in FIG. 6(comprising the metallic electrode 112 with an impedance discontinueingpattern and an alumina ceramic material as the insulating material 111plasma-sprayed to the surface of the electrode 112 in a state with noclearance) according to the present invention, said eight lightreceiving members were prepared in accordance with the previouslydescribed film-forming procedures using the plasma CVD apparatus shownin FIGS. 9(a) and 9(b) and under film-forming conditions shown in Table25. It should be noted that the thicknesses mentioned in Table 25 arerough values.

[0328] For the resultant light receiving members, evaluation wasconducted with respect to occurrence of spherical growth defect in theirsurface, occurrence of uneven image density in the image reproduction,and occurrence of black dot in the image reproduction in the same manneras in Experiment 6. The evaluated results obtained are collectivelyshown in Table 29.

EXAMPLE 9

[0329] In this example, there were prepared eight light receivingmembers of the configuration shown in FIG. 20 in the following manner.

[0330] Using the plasma CVD apparatus shown in FIGS. 9(a) and 9(b)having the high frequency power introduction means shown in FIG. 7(comprising the metallic electrode 112 with an impedance discontinueingpattern and a titanium dioxide material as the insulating material 111plasma-sprayed to the surface of the electrode 112 in a state with noclearance) according to the present invention, said eight lightreceiving members were prepared in accordance with the previouslydescribed film-forming procedures using the plasma CVD apparatus shownin FIGS. 9(a) and 9(b) and under film-forming conditions shown in Table26. It should be noted that the thicknesses mentioned in Table 26 arerough values.

[0331] For the resultant light receiving members, evaluation wasconducted with respect to occurrence of spherical growth defect in theirsurface, occurrence of uneven image density in the image reproduction,and occurrence of black dot in the image reproduction in the same manneras in Experiment 6. The evaluated results obtained are collectivelyshown in Table 29.

EXAMPLE 10

[0332] In this example, there were prepared eight light receivingmembers of the configuration shown in FIG. 20 in the following manner.

[0333] Using the plasma CVD apparatus shown in FIGS. 9(a) and 9(b)having the high frequency power introduction means shown in FIG. 8(comprising the metallic electrode 112 with an impedance discontinueingpattern and an alumina ceramic material as the insulating material 111plasma-sprayed to the surface of the electrode 112 in a state with noclearance and having the cooling mechanism) according to the presentinvention, said eight light receiving members were prepared inaccordance with the previously described film-forming procedures usingthe plasma CVD apparatus shown in FIGS. 9(a) and 9(b) and underfilm-forming conditions shown in Table 27. It should be noted that thethicknesses mentioned in Table 27 are rough values.

[0334] For the resultant light receiving members, evaluation wasconducted with respect to occurrence of spherical growth defect in theirsurface, occurrence of uneven image density in the image reproduction,and occurrence of black dot in the image reproduction in the same manneras in Experiment 6. The evaluated results obtained are collectivelyshown in Table 29.

EXAMPLE 11

[0335] In this example, there were prepared eight light receivingmembers of the configuration shown in FIG. 20 in the following manner.

[0336] Using the plasma CVD apparatus shown in FIGS. 22(a) and 22(b)having the high frequency power introduction means shown in FIG. 8(comprising the metallic electrode 112 with an impedance discontinueingpattern and an alumina ceramic material as the insulating material 111plasma-sprayed to the surface of the electrode 112 in a state with noclearance and having the cooling mechanism) according to the presentinvention, said eight light receiving members were prepared inaccordance with the previously described film-forming procedures usingthe plasma CVD apparatus shown in FIGS. 22(a) and 22(b) and underfilm-forming conditions shown in Table 28. It should be noted that thethicknesses mentioned in Table 28 are rough values.

[0337] For the resultant light receiving members, evaluation wasconducted with respect to occurrence of spherical growth defect in theirsurface, occurrence of uneven image density in the image reproduction,and occurrence of black dot in the image reproduction in the same manneras in Experiment 6. The evaluated results obtained are collectivelyshown in Table 29.

Total Evaluation

[0338] Each of the valuated values for the number of a spherical growthdefect and the uneven image density obtained in each of Examples 8 to 11shown in Table 29 is a value relative to the corresponding evaluatedvalue obtained in Example 7, which is set at 1.

[0339] Based on the results shown in Table 29, it is understood that thelight receiving members obtained in Examples 7 to 11 are quitesatisfactory for all the evaluation items.

[0340] As apparent from the above description, the high frequency powerintroduction means according to the present invention provides varioussignificant advantages. Particularly, because the surface thereof to beexposed to a plasma generated in the glow discharge zone is covered by ainsulating base material, the adhesion of a film deposited thereon isgood enough, where problems due to layer peeling are not occurred. Inaddition, because the electrode is covered by said insulating materialin such structure that the impedance is discontinued, the impedancediscontinueing face effectively acts with the face of reflecting a highfrequency power to unify the distribution of a high frequency power. Bythis, even in the case where the electrode of the high frequency powerintroduction means is made to have a complicated structure with animpedance discontinueing pattern, the occurrence of sparking iseffectively prevented. Further, by forming the electrode such a mannerthat it is joined to the inside of the insulating material in a statewith no clearance between them, the occurrence of an uneven highfrequency power distribution due to the clearance between the electrodeand the insulating cover which is found in the prior art is effectivelyprevented.

[0341] According to the present invention, not only the occurrence oflayer peeling for a film deposited on the surface of a high frequencypower introduction means but also the occurrence of localization of aplasma generated are effectively prevented. This makes it possible toeffectively form various high quality deposited films while effectivelypreventing not only the occurrence a spherical growth defect but alsothe occurrence of an unevenness in layer thickness. This enables toefficiently produce a high quality light receiving member, particularly,a high quality electrophotographic light receiving member excelling inimage-forming characteristics and which reproduces a high quality imagewith an improved uniform image density and with neither minute blankarea nor black dot.

[0342] The present invention is not limited to the foregoing experimentsand examples but it can be optionally modified in a range where theprinciple of the present invention is not hindered. It is a matter ofcause that the product produced according to the present invention isnot limited to an electrophotographic light receiving member.

[0343] However, the present invention is quite suitable for theproduction of an electrophotographic light receiving member in which thedeposition of a large area deposited film having a homogenous propertyis desired to be formed at a high speed. TABLE 1 raw material gas andflow rate SiH₄ (sccm) 250 substrate temperature (° C.) 280 innerpressure (Pa) 2 high frequency power (w) 4000 oscillation frequency(MHz) 105

[0344] TABLE 2 raw material gas and flow rate SiH₄ (sccm) 200 substratetemperature (° C.) 230 inner pressure (Pa) 1 high frequency power (w)3000 oscillation frequency (MHz) 105

[0345] TABLE 3 constituent charge injection photoconductive surfacelayer inhibition layer layer layer raw material gas and flow rate SiH₄(sccm) 500 1000 120 H₂ (sccm) 500 B₂H₆ (ppm) 1000 2 (against SiH₄) CH₄(sccm) 500 substrate 250 250 250 tenperature (° C.) inner 6 4 4 pressure(Pa) high frequency 5000 6000 3000 power (w) (105 MHz) layer 3 30 0.5thickness (μm)

[0346] TABLE 4 raw material gas and flow rate SiH₄ (sccm) 250 substratetemperature (° C.) 280 inner pressure (Pa) 2 high frequency power (w)500 oscillation frequency (MHz) 105

[0347] TABLE 5 constituent charge injection photoconductive surfacelayer inhibition layer layer layer raw material gas and flow rate SiH₄(sccm) 500 250 80 H₂ (sccm) 500 B₂H₆ (ppm) 1000 2 (against SiH₄) CH₄(sccm) 500 substrate 250 250 250 tenperature (° C.) inner 6 4 4 pressure(Pa) high frequency 2500 2500 1000 power (w) (105 MHz) layer 3 30 0.5thickness (μm)

[0348] TABLE 6 constituent charge injection photoconductive surfacelayer inhibition layer layer layer raw material gas and flow rate SiH₄(sccm) 150 200 20 B₂H₆ (ppm) 1000 0.2 (against SiH₄) CH₄ (sccm) 200substrate 210 210 210 tenperature (° C.) inner 6 4 4 pressure (Pa) highfrequency 1500 changed 1000 power (w) (105 MHz) layer 3 30 0.5 thickness(μm)

[0349] TABLE 7 high frequency power (w) 500 1000 1500 2000 3000 5000unevenness in 0.96 0.92 1 1.03 1.06 0.98 image density No. of spherical1.05 1.05 1 0.95 0.92 1.04 growth defect appearance of ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ blackdot

[0350] TABLE 8 high frequency power (w) 500 1000 1500 2000 3000 5000unevenness in 0.79 0.81 0.82 0.87 0.95 0.98 image density No. ofspherical 1.06 1.02 0.96 1.05 0.98 1.03 growth defect appearance of ⊚ ⊚∘ ∘ ∘ ∘ black dot

[0351] TABLE 9 high frequency power (w) 500 1000 1500 2000 3000 5000unevenness in 0.86 0.87 0.89 0.91 0.92 0.96 image density No. ofspherical 5.3  4.6  4.8  4.3  4.7  5.1  growth defect appearance of ⊚ ⊚⊚ ⊚ ∘ ∘ black dot

[0352] TABLE 10 constituent charge injection photoconductive surfacelayer inhibition layer layer layer raw material gas and flow rate SiH₄(sccm) 250 250 20 B₂H₆ (ppm) 1000 0.2 (against SiH₄) CH₄ (sccm) 200substrate 210 210 210 tenperature (° C.) inner 2 2 2 pressure (Pa) highfrequency 1500 1500 500 power (w) (105 MHz) layer 3 20 0.5 thickness(μm)

[0353] TABLE 11 oscillation 13.56 20 60 105 450 800 frequency (MHz)unevenness in X 1.03 0.95 1 0.92 0.63 image density No. of spherical X1.08 1.03 1 1.06 0.95 growth defect appearance of X ⊚ ⊚ ⊚ ⊚ ⊚ blackdot

[0354] TABLE 12 constituent charge injection photoconductive surfacelayer inhibition layer layer layer raw material gas and flow rate SiH₄(sccm) 500 350 120 B₂H₆ (ppm) 500 1 (against SiH₄) CH₄ (sccm) 700substrate 300 300 150 temperature (° C.) inner 5 3 2 pressure (Pa) highfrequency 5000 5000 3000 power (w) (105 MHz) layer 5 30 0.5 thickness(μm)

[0355] TABLE 13 Comparative Comparative Example 1 Example 1 Example 2No. of spherical 1 1.1 3.8 growth defect unevenness in 1 0.76 1.05 layerthickness unevenness in 1 0.68 0.98 image density

[0356] TABLE 14 constituent charge injection photoconductive surfacelayer inhibition layer layer layer raw material gas and flow rate SiH₄(sccm) 300 350 120 B₂H₆ (ppm) 1000 1 (against SiH₄) CH₄ (sccm) 1000substrate 350 350 350 temperature (° C.) inner 5 3 2 pressure (Pa) highfrequency 3000 3000 3000 power (w) (oscillation frequency changed) layer2 15 0.5 thickness (μm)

[0357] TABLE 15 oscillation 20 50 105 200 450 frequency (MHz) No. ofspherical 1.1 0.95 1 1 0.95 growth defect unevenness in 0.98 1.03 1 0.981.02 layer thickness unevenness in 1.06 1.02 1 0.97 1.03 image density

[0358] TABLE 16 constituent charge injection photoconductive surfacelayer inhibition layer layer layer raw material gas and flow rate SiH₄(sccm) 600 500 300 B₂H₆ (ppm) 1000 3 (against SiH₄) CH₄ (sccm) 1000substrate 350 350 350 temperature (° C.) inner 5 3 2 pressure (Pa) highfrequency 4000 5000 5000 power (w) (oscillation frequency changed) layer2 15 0.5 thickness (μm)

[0359] TABLE 17 oscillation 20 50 105 200 450 frequency (MHz) No. ofspherical 0.95 0.95 1.05 1.05 0.95 growth defect unevenness in 0.96 0.980.98 1.02 0.97 layer thickness unevenness in 0.98 1.04 1.02 0.97 1.01image density

[0360] TABLE 18 constituent charge injection photoconductive surfacelayer inhibition layer layer layer raw material gas and flow rate SiH₄(sccm) 250 750 300 B₂H₆ (ppm) 700 0.5 (against SiH₄) CH₄ (sccm) 1000substrate 280 280 150 temperature (° C.) inner 5 3 1 pressure (Pa) highfrequency 3000 3000 3500 power (w) (oscillation frequency changed) layer3 25 0.5 thickness (μm)

[0361] TABLE 19 oscillation 20 50 105 200 450 frequency (MHz) No. ofspherical 0.95 1 1 1 0.95 growth defect unevenness in 1.01 1.01 0.961.01 0.99 layer thickness unevenness in 0.96 1.02 1.03 0.96 1.01 imagedensity

[0362] TABLE 20 constituent charge injection photoconductive surfacelayer inhibition layer layer layer raw material gas and flow rate SiH₄(sccm) 250 300 150 B₂H₆ (ppm) 700 0.5 (against SiH₄) CH₄ (sccm) 650substrate 280 280 150 temperature (° C.) inner 3 3 1 pressure (Pa) highfrequency 500 800 500 power (w) (oscillation frequency changed) layer 325 0.5 thickness (μm)

[0363] TABLE 21 oscillation frequency (MHz) 20 50 105 200 450 No. ofspherical 0.95 1 0.95 1 1.05 growth defect unevenness in 1.01 0.98 0.981.01 0.97 layer thickness unevenness in 1.01 0.95 1.01 0.98 0.98 inagedensity

[0364] TABLE 22 constituent charge injection photoconductive surfacelayer inhibition layer layer layer raw material gas and flow rate SiH₄(sccm) 100 250 60 B₂H₆ (ppm) 500 0.5 (against SiH₄) CH₄ (sccm) 500substrate 250 250 220 temperature (° C.) inner 3 3 3 pressure (Pa) highfrequency 3000 3000 3500 power (w) (oscillation frequency changed) layer1.5 25 0.5 thickness (ρm)

[0365] TABLE 23 oscillation frequency (MHz) 20 50 105 200 450 No. ofspherical 1 0.95 1 1 0.95 growth defect unevenness in 0.98 1.01 1.021.01 1.04 layer thickness unevenness in 0.96 0.98 1.03 1.03 0.96 inagedensity

[0366] TABLE 24 constituent charge injection photoconductive surfacelayer inhibition layer layer layer raw material gas and flow rate SiH₄(sccm) 350 350 120 B₂H₆ (ppm) 500 1 (against SiH₄) CH₄ (sccm) 500 NO(sccm) 15 substrate 300 300 150 temperature (° C.) inner 5 3 3 pressure(Pa) high frequency 2000 2000 1000 power (w) (60 MHz) layer 3 20 0.5thickness (ρm)

[0367] TABLE 25 constituent charge injection photoconductive surfacelayer inhibition layer layer layer raw material gas and flow rate SiH₄(sccm) 100 100 20 B₂H₆ (ppm) 300 0.1 (against SiH₄) CH₄ (sccm) 100substrate 250 250 250 temperature (° C.) inner 2 2 2 pressure (Pa) highfrequency 2000 2000 600 power (w) (105 MHz) layer 2 15 0.5 thickness(ρm)

[0368] TABLE 26 constituent charge injection photoconductive surfacelayer inhibition layer layer layer raw material gas and flow rate SiH₄(sccm) 300 300 300 B₂H₆ (ppm) 1000 3 (against SiH₄) CH₄ (sccm) 1000substrate 350 350 350 temperature (° C.) inner 3 3 2 pressure (Pa) highfrequency 3000 5000 1800 power (w) (105 MHz) layer 2 20 0.5 thickness(ρm)

[0369] TABLE 27 constituent charge injection photoconductive surfacelayer inhibition layer layer layer raw material gas and flow rate SiH₄(sccm) 300 300 300 B₂H₆ (ppm) 1000 3 (against SiH₄) CH₄ (sccm) 1000substrate 350 350 350 temperature (° C.) inner 3 3 2 pressure (Pa) highfrequency 3000 5000 1800 power (w) (105 MHz) layer 2 20 0.5 thickness(ρm)

[0370] TABLE 28 constituent charge injection photoconductive surfacelayer inhibition layer layer layer raw material gas and flow rate SiH₄(sccm) 300 300 300 B₂H₆ (ppm) 3000 3 (against SiH₄) CH₄ (sccm) 1000 NO(sccm) 15 substrate 350 350 350 temperature (° C.) inner 3 3 2 pressure(Pa) high frequency 3000 5000 1800 power (w) (105 MHz) layer 2 20 0.5thickness (ρm)

[0371] TABLE 29 Example Example Example 7 Example 8 Example 9 10 11 No.of 1 0.95 1.05 1.06 0.98 spherical growth defect unevenness 1 0.98 0.961.02 0.98 in image density appearance ⊚ ⊚ ⊚ ⊚ ⊚ of black dot

What is claimed is:
 1. A deposited film-forming apparatus comprising areaction chamber capable of being vacuumed in which glow discharge iscaused by means of a high frequency power supplied by a high frequencypower introduction means to form a deposited film on a substratepositioned in said reaction chamber, wherein said high frequency powerintroduction means comprises an insulating material as a baseconstituent and has a region isolated from a glow discharge zone of saidreaction chamber by means of said insulating material wherein anelectrode comprising an electrically conductive metallic material havinga thickness capable of sufficiently transmitting said high frequencypower is disposed in said region such that it is contacted with saidinsulating material in a state with no clearance.
 2. A depositedfilm-forming apparatus according to claim 1, wherein the electricallyconductive material constituting the electrode has an impedancediscontinueing pattern and is contacted with the insulating material ina state with no clearance.
 3. A deposited film-forming apparatusaccording to claim 2, wherein the impedance discontinueing pattern is ofa configuration in which the high frequency power propagation path ispartly branched into plural portions.
 4. A deposited film-formingapparatus according to claim 2, wherein the impedance discontinueingpattern is of a configuration in which a part of the high frequencypower propagation path is turned up.
 5. A deposited film-formingapparatus according to claim 2, wherein the impedance discontinueingpattern is of a coil-like configuration.
 6. A deposited film-formingapparatus according to claim 1, wherein the insulating material is aceramic material.
 7. A deposited film-forming apparatus according toclaim 1, wherein the high frequency power introduction means is providedwith a cooling mechanism.
 8. A deposited film-forming apparatusaccording to claim 1, wherein the high frequency power introductionmeans is provided with a heating mechanism.
 9. A deposited film-formingapparatus according to claim 1, wherein the high frequency powerintroduction means serves as a raw material gas introduction means. 10.A deposited film-forming apparatus according to claim 1, wherein theinsulating material has a portion to be exposed to the glow dischargezone and said portion has a surface roughness of 5 μm to 200 μm in termsof JIS ten-point average roughness (RZ) under JIS B0601.
 11. A depositedfilm-forming apparatus according to claim 1, wherein the insulatingmaterial is an alumina ceramic material.
 12. A deposited film-formingapparatus according to claim 1, wherein the substrate comprises aplurality of cylindrical substrates and said plurality of cylindricalsubstrates are made to be capable of spacedly and concentricallyarranging so as to circumscribe the glow discharge zone.
 13. A depositedfilm-forming apparatus according to claim 2, wherein the insulatingmaterial is a ceramic material.
 14. A deposited film-forming apparatusaccording to claim 2, wherein the high frequency power introductionmeans is provided with a cooling mechanism.
 15. A deposited film-formingapparatus according to claim 2, wherein the high frequency powerintroduction means is provided with a heating mechanism.
 16. A depositedfilm-forming apparatus according to claim 2, wherein the high frequencypower introduction means serves as a raw material gas introductionmeans.
 17. A deposited film-forming apparatus according to claim 2,wherein the insulating material has a portion to be exposed to the glowdischarge zone and said portion has a surface roughness of 5 μm to 200μm in terms of JIS ten-point average roughness (RZ) under JIS B0601. 18.A deposited film-forming apparatus according to claim 2, wherein theinsulating material is an alumina ceramic material.
 19. A depositedfilm-forming apparatus according to claim 2, wherein the substratecomprises a plurality of cylindrical substrates and said plurality ofcylindrical substrates are made to be capable of spacedly andconcentrically arranging so as to circumscribe the glow discharge zone.20. A deposited film-forming process comprising introducing a rawmaterial gas and a high frequency power into a reaction chamber capableof being vacuumed and containing a substrate positioned therein to causeglow discharge by means of said high frequency power whereby forming adeposited film on said substrate, wherein the introduction of said highfrequency power into said reaction chamber is conducted by a highfrequency power introduction means comprising an insulating material asa base constituent and having a region isolated from a glow dischargezone of said reaction chamber by means of said insulating materialwherein an electrode comprising an electrically conductive metallicmaterial having a thickness capable of sufficiently transmitting saidhigh frequency power is disposed in said region such that it iscontacted with said insulating material in a state with no clearance.21. A deposited film-forming process according to claim 20, wherein theelectrically conductive material constituting the electrode has animpedance discontinueing pattern.
 22. A deposited film-forming processaccording to claim 20, wherein the high frequency power is of anoscillation frequency in the range of from 20 MHz to 450 MHz.
 23. Adeposited film-forming process according to claim 20, wherein the highfrequency power introduction means is cooled.
 24. A depositedfilm-forming process according to claim 20, wherein the high frequencypower introduction means is heated.
 25. A deposited film-forming processaccording to claim 20, wherein the substrate comprises a plurality ofcylindrical substrates and said plurality of cylindrical substrates arespacedly and concentrically arranged so as to circumscribe the glowdischarge zone.
 26. A deposited film-forming process according to claim21, wherein the high frequency power introduction means is cooled.
 27. Adeposited film-forming process according to claim 21, wherein the highfrequency power introduction means is heated.
 28. A depositedfilm-forming process according to claim 21, wherein the high frequencypower is of an oscillation frequency in the range of from 20 MHz to 450MHz.
 29. A deposited film-forming process according to claim 21, whereinthe impedance discontinueing pattern is of a configuration in which thehigh frequency power propagation path is partly branched into pluralportions.
 30. A deposited film-forming process according to claim 21,wherein the impedance discontinueing pattern is of a configuration inwhich a part of the high frequency power propagation path is turned up.31. A deposited film-forming process according to claim 21, wherein theimpedance discontinueing pattern is of a coil-like configuration.
 32. Adeposited film-forming process according to claim 21, wherein thesubstrate comprises a plurality of cylindrical substrates and saidplurality of cylindrical substrates are spacedly and concentricallyarranged so as to circumscribe the glow discharge zone.